Mandy TRIPP 

v.

SCOTT EMERGENCY COMMUNICATION CENTER and Iowa Municipalities Workers' Compensation Association

Judges: McDermott, J., delivered the opinion of the court in which Christensen, C.J., and Appel and Oxley, JJ., joined. Christensen, C.J., filed a concurring opinion. Waterman, J., filed a dissenting opinion, in which Mansfield and McDonald, JJ., joined.

McDERMOTT, Justice.

This case requires us to determine whether Iowa's workers' compensation statute places on emergency responders a different, higher bar to be eligible for benefits for trauma-induced mental injuries suffered on the job than workers in other roles with identical injuries.

Mandy Tripp, a sixteen-year veteran of Scott County's emergency dispatch system, answered a 911 call from a woman screaming over and over at a high pitch, "Help me, my baby is dead." The woman's screams continued for more than two minutes. Tripp eventually got the woman's address and dispatched first responders. She soon heard a report from a police officer that arrived on the scene about finding a dead infant that appeared to have been attacked with a claw hammer.

In the months that followed, Tripp couldn't shake the mother's screams from her mind or her ears. Loud noises, in particular, would trigger debilitating anxiety. Tripp sought medical help. A counselor and two doctors diagnosed her with PTSD resulting from the call. She was prescribed medication to address the PTSD and wore special headphones to drown out loud noises, sometimes even wearing special musicians' earplugs under larger noise-canceling headphones. It helped, but not enough. Tripp found herself unable to perform her job duties as an emergency dispatcher as she had before.

Iowa's workers' compensation law permits workers to receive compensation for injuries that they suffer arising from and in the course of their jobs. Injuries from mental trauma suffered on the job have long been recognized as a basis to provide workers' compensation. But when Tripp applied for workers' compensation based on her PTSD, her request was denied. Tripp didn't satisfy the test of legal causation, according to the workers' compensation commissioner and district court, because 911 dispatchers routinely take calls involving death and traumatic injury, and the mother's harrowing call thus wasn't an "unexpected cause or unusual strain." Tripp appeals. Because Tripp has established that her PTSD resulted from a manifest happening of a sudden traumatic nature from an unexpected cause or unusual strain, we hold she is entitled to workers' compensation benefits.

I.

Tripp began her career as an emergency dispatcher in 2002, first with the Davenport Police Department and then (when the police department's emergency dispatch system later combined with the county's system) with the Scott County Emergency Communications Center (SECC). Tripp soon was tabbed to train other emergency dispatchers. In a typical workday, Tripp estimated that she answered anywhere from 50 to 200 calls, including 911 emergency and nonemergency calls and administrative calls. An average call lasts thirty-five seconds.

On September 30, 2018, Tripp answered a 911 call from a woman "screaming at a very high pitch, 'Help me, my baby is dead. Help me, my baby is dead,' over and over and over." The screaming continued for two minutes and fifteen seconds. Tripp struggled to calm the women enough to get an address to dispatch an ambulance. She ultimately got an address and transferred the call to a medical dispatcher who tried to instruct the mother on lifesaving measures until the ambulance arrived.

Tripp continued to hear ongoing radio traffic about the incident after she transferred the call. She heard the medical dispatcher tell the mother how to perform CPR on an infant. She heard the emergency medics who arrived by ambulance at the scene say that "[r]igor was already set in." And she heard police officers talking about "a potential crime scene" at the mother's home. Injuries to the child's face, according to one investigating officer speaking over the radio, suggested that the child had been beaten with a claw hammer. All the while, the child's mother screamed in the background.

Tripp's supervisor asked Tripp if she needed a break. Tripp declined, responding that she "needed another call" to get the mother's screams "out of my head." Tripp texted her husband, Dennis, a Bettendorf Police Officer with twenty-three years' experience in law enforcement. She told him that she'd taken "a really bad phone call" and needed to talk to him just to hear another voice. It was, according to Dennis, the first time that she'd ever requested such a thing. Tripp remained at work and continued taking calls until her shift ended.

In the days that followed, Tripp was on the verge of tears, didn't want to answer calls, and didn't want to talk with anyone. Although she had taken emergency calls involving serious injuries to children in the past from people at the scene of fatal incidents, including three calls involving a dead infant, she had never before answered a call from a dead child's own mother. Tripp described the mother's screams as something beyond "normal" sounds: "guttural, awful." Tripp confided to her supervisor and several coworkers that she was struggling to deal with the call. She found herself constantly crying, unable to process her emotions, wanting to sleep, and becoming socially withdrawn.

Tripp initially sought treatment with Lisa Beecher, a licensed mental health counselor, to help her address her mental health, which had been in a state of freefall since the call. Tripp's employer approved the visit. Tripp saw Beecher at least five times over about a three-week period. Beecher diagnosed Tripp with post-traumatic stress disorder, a mental health condition commonly referred to by its acronym: "PTSD." Tripp took two weeks off work at Beecher's suggestion. When she returned to work, she did so with restricted hours.

Beecher soon determined that Tripp's condition wasn't improving. Beecher referred her to a psychologist, Dr. Robert Gillespie, who had treated other Davenport first responders and police officers. Gillespie also diagnosed Tripp with PTSD. He instructed her to seek medication from her regular physician to treat it. Tripp's physician prescribed her an antidepressant. Tripp took the prescribed antidepressants and continued to see Beecher for counseling and Gillespie for psychotherapy to treat her PTSD.

Gillespie's notes of his meeting with Tripp in April 2019 (more than six months after the call) recount that Tripp had been having suicidal feelings at work but had been able to work through them. She continued to struggle with "heightened levels of emotional responsivity" brought on by certain sounds, particularly high-pitched voices. And she continued to experience episodic recurrence of traumatic stress, but with some improvement in the frequency and intensity of the episodes.

In September 2019, another psychiatrist, Martin Carpenter, M.D., performed an independent psychiatric evaluation of Tripp for this litigation. He also diagnosed Tripp's condition as PTSD. Carpenter consulted the Diagnostic and Statistical Manual of Mental Disorders (the DSM-5), the fifth edition of a diagnosis manual for psychological disorders, in making his diagnosis. The DSM-5 states that PTSD can result from exposure "to actual or threatened death," either through directly experiencing a traumatic event or experiencing "repeated or extreme exposure to aversive details of" a traumatic event. Am. Psychiatric Ass'n, Diagnostic and Statistical Manual of Mental Disorders 271 (5th. ed. 2013). Carpenter recommended that Tripp, on top of her ongoing prescription drug treatment, use physical interventions to address her PTSD symptoms. Among other things, Carpenter recommended that she wear special earplugs to limit hearing loud noises, which were a significant trigger of anxiety since the incident.

Tripp filed an application for workers' compensation benefits based on her PTSD. At the evidentiary hearing, both Beecher and Gillespie's reports found that Tripp's PTSD resulted directly from her involvement in the traumatic events of the mother's 911 call. Gillespie noted that the fourth edition of the DSM "explicitly contemplates the exposure risk for first responders, such as 911 operators." Gillespie testified to his opinion that, by May 2019, Tripp had reached "maximum medical improvement"—in other words, had achieved all the improvement that she reasonably would ever be expected to achieve—as to her PTSD. Tripp's PTSD thus, according to Gillespie, constituted a "chronic episodic condition" resulting in a permanent disability.

Carpenter similarly found that Tripp's diagnosis resulted directly from the events of the mother's 911 call. He concluded that Tripp's condition satisfied the PTSD criteria in the DSM-5 as a "traumatic exposure" in which she experienced a mother's discovery of a dead child in vivid and disturbing fashion. Carpenter also agreed that Tripp had reached maximum medical improvement and that she'd need both ongoing pharmacological management and psychotherapy to treat her PTSD.

Tripp's employer, the SECC, contested her petition for workers' compensation and called three of Tripp's coworkers to testify at the evidentiary hearing: a medical dispatcher with twenty-four years' experience (in fact, the same medical dispatcher who instructed the mother on CPR), the SECC's director (who previously worked as a dispatcher), and the SECC's deputy director (who also previously worked as a dispatcher). Each testified to their belief that calls such as the one that brought on Tripp's PTSD weren't unusual or unexpected. They provided various estimates of similar calls based on their experience. One acknowledged that she'd fielded around 141,000 calls in her career and about a dozen involved an infant's death; another estimated she'd taken about 572,000 calls of which fifteen involved a child's death. Tripp's current supervisor testified that the SECC provided Tripp with accommodations for her PTSD, including light-duty work, changing her seating arrangement when possible, and allowing her to leave if she experiences an anxiety-triggering call. No witness disputed any testimony from Tripp's medical professionals.

Tripp agreed that fielding a 911 call from a distraught person was neither unexpected nor unusual in an emergency dispatcher's work and that speaking with crying or even incoherent callers was a normal part of the job. Tripp also acknowledged that she'd fielded traumatic calls since the incident, including a call involving the suicide of a teenager (which, as reported in Gillespie's notes, caused Tripp to hear the mother's screams in her head from the earlier call and to start crying). And despite her sensitivity to loud sounds since the call, Tripp had personally attended a large business convention, although she wore noise-canceling headphones on top of musician's earplugs during the convention. Tripp applied for a job as a librarian because of her sensitivity to sound. Tripp still tries, in her words, to "participate in life" despite her PTSD and wants to continue to work as an emergency dispatcher to the extent she's able to because she "love[s] the job."

Her husband Dennis testified that after the call, his wife had become withdrawn and unable to engage in many normal social activities, primarily because of her new sensitivity to loud sounds. Dennis saw some improvement in her condition from the psychotherapy and prescription drug treatments. He agreed that 911 operators anticipate taking emergency calls by nature of their jobs and agreed that a parent whose infant was dying would call 911 and be distraught. Dennis, for his part, has never in his career been called to respond to a matter involving a dead infant and would characterize such an event as unusual.

After hearing the evidence, the deputy workers' compensation commissioner denied Tripp's petition for benefits. Although acknowledging it was "a difficult case," the deputy commissioner held that because 911 dispatchers "routinely" take calls involving death and traumatic injuries, Tripp failed to prove that the PTSD-inducing call was "unusual" or "unexpected" as required under our court's prior mental injury cases. Tripp moved for rehearing, which the deputy denied. Tripp appealed to the workers' compensation commissioner, who affirmed the deputy's decision. Tripp then sought judicial review in the district court, which likewise affirmed the prior ruling. She appeals that ruling.

II.

The parties disagree on our standard of review. Tripp argues that we review for legal error because the standard for establishing a purely mental injury is an issue of law. The SECC argues that we must defer to the commission because legal causation is based on findings of fact, which should be upheld as long as substantial evidence in the record supports those findings.

The commission's decision involves an application of law to the facts and thus presents a mixed question of law and fact. Meyer v. IBP, Inc., 710 N.W.2d 213, 219 (Iowa 2006). If the claimed error pertains to the agency's findings of fact, then "the proper question on review is whether substantial evidence supported those" factual findings. Id. But if the claimed error pertains to the agency's interpretation of the law, then the question on review is whether the agency's interpretation was wrong. Id. We don't defer to the commission's interpretation of the legal standard to prove a purely mental injury under Iowa law. Dunlavey v. Econ. Fire & Cas. Co., 526 N.W.2d 845, 849 (Iowa 1995); see also Iowa Code § 17A.19(10)(c) (2019). That legal standard presents a legal question, and we're thus not bound by the agency's conclusions and instead substitute our own judgment. Lakeside Casino v. Blue, 743 N.W.2d 169, 173 (Iowa 2007).

III.

Iowa's workers' compensation system is a creature of statute, being both conceived and constructed by legislative action. See Hansen v. State, 249 Iowa 1147, 91 N.W.2d 555, 556-57 (Iowa 1958). The system provides mutual benefits and tradeoffs for workers and employers. Harned v. Farmland Foods, Inc., 331 N.W.2d 98, 100 (Iowa 1983) (en banc). Workers relinquish their right to sue the employer for damages on the condition that the employer promptly compensates workers for injuries that arise out of and in the course of employment regardless of fault. Baker v. Bridgestone/Firestone, 872 N.W.2d 672, 676-77 (Iowa 2015).

Our analysis centers on Iowa Code section 85.3(1), which establishes a worker's eligibility to receive, and an employer's duty to pay, workers' compensation. It states:

Every employer . . . shall provide, secure, and pay compensation according to the provisions of this chapter for any and all personal injuries sustained by an employee arising out of and in the course of the employment, and in such cases, the employer shall be relieved from other liability for recovery of damages or other compensation for such personal injury.

Iowa Code § 85.3(1). Interpreting the plain language of the statute, the question presented in this appeal has two parts: (1) whether Tripp's PTSD is a "personal injury," and (2) whether she sustained it "arising out of and in the course of" her job as an emergency dispatcher. If the answer to both parts is yes, she's entitled to compensation; if not, then not.

Does Tripp's PTSD constitute a "personal injury" under the statute? The terms "injury" and "personal injury" are elaborated on, although not necessarily defined, in section 85.61(4). That section states that these terms "shall be construed as follows" and then states that "they shall include death resulting from personal injury" and "shall not include a disease unless it shall result from the injury and they shall not include an occupational disease." Id. § 85.61(4)(a), (b). Neither elaboration provides any help in this case since Tripp didn't die and her PTSD isn't a disease.

In Dunlavey v. Economy Fire & Casualty Co., we analyzed whether an employee's "nontraumatic mental injury"—in that case, major depressive disorder—amounted to a "personal injury" under section 85.3(1). 526 N.W.2d at 849-53. The employer argued that, as a matter of public policy, we should refuse to recognize psychological injuries without an associated physical injury (referred to as a "mental-mental injury") because it would breed fraudulent and unverifiable workers' compensation claims by employees. Id. at 856. But after surveying cases from states around the country with similarly-worded workers' compensation statutes, finding no expression by the legislature in our statute to carve out a restriction for purely psychological injuries, and further finding "no really valid distinction between physical and 'nervous' injury," we held that psychological injuries met the definition of "personal injuries" under the statute. Id. at 851, 853 (quoting 1B Arthur Larson, The Law of Workmen's Compensation § 42.23(a), at § 7-906 (1993)). As to whether PTSD in particular qualifies, in Brown v. Quik Trip Corp., we held that a convenience store clerk's PTSD diagnosis met the definition. 641 N.W.2d 725, 727-29 (Iowa 2002). Tripp's PTSD diagnosis thus likewise qualifies as a "personal injury" under the statute.

Turning to the second part of the statutory inquiry: Does Tripp's PTSD arise "out of and in the course of the employment"? In Dunlavey, we said that an employee seeking compensation for a mental injury required proof of both "medical causation" and "legal causation." 526 N.W.2d at 853. Medical causation requires the employee to show "that the alleged mental condition was in fact caused by employment-related activities." Asmus v. Waterloo Cmty. Sch. Dist., 722 N.W.2d 653, 657 (Iowa 2006). Legal causation, on the other hand, requires the employee to show that the mental injury resulted from "workplace stress of greater magnitude than the day-to-day mental stresses experienced by other workers employed in the same or similar jobs, regardless of their employer." Dunlavey, 526 N.W.2d at 858.

But in Brown, we walked back part of the causation burden we'd previously imposed on employees in Dunlavey. 641 N.W.2d at 728-29. In Brown, we overturned the commissioner's denial of benefits for a convenience store clerk who developed PTSD after seeing a customer get shot and, about a week later, had been held up at work by an apparently armed robber. Id. at 726-27. We formulated a different standard of causation when an employee establishes that the mental injury at issue is "based on a manifest happening of a sudden traumatic nature from an unexpected cause or unusual strain." Id. at 729. Such a situation meets the legal-causation test "irrespective of the absence of similar stress on other employees." Id. We could dispense with the legal-causation requirement in such a circumstance, we reasoned, because a mental injury that occurred rapidly and could be traced to a specific, sudden event had a sufficiently strong "badge of reliability" (in contrast to a mental injury alleged to have developed gradually over time). Id. at 728 (quoting Graves v. Utah Power & Light Co., 713 P.2d 187, 192 (Wyo. 1986), superseded by statute as stated in Brown, 641 N.W.2d at 728 n.1).

Neither Brown nor any of our cases since have explored the contours of what "manifest happening of a sudden traumatic nature from an unexpected cause or unusual strain" means. Id. at 729. The SECC argues that Brown requires the factfinder to focus on that employee's particular job duties to determine whether the injury-causing incident was an "unexpected cause or unusual strain" under Iowa Code section 85.3(1). Tripp, conversely, in effect argues that Brown requires the factfinder to focus on whether the sudden event constitutes an "unexpected cause or unusual strain" in employment life generally, without regard to the regular duties of the particular employee or employees in similar positions. The deputy commissioner adopted the SECC's proposed interpretation. The commissioner and district court agreed, with the district court noting that the "baseline seems to be most appropriately drawn by looking to the unique features of each particular claimant's experiences—including their ordinary workplace activities."

In Brown, we adopted the phrase "manifest happening of a sudden traumatic nature from an unexpected cause or unusual strain" from the test we found in a Montana case, Tocco v. City of Great Falls, to determine whether an injury met the legal standard for workers' compensation. Brown, 641 N.W.2d at 729 (citing Tocco v. City of Great Falls, 220 Mont. 221, 714 P.2d 160, 163-64 (Mont. 1986)). But the Montana Supreme Court in Tocco was quoting a phrase from Montana's own workers' compensation statute, Montana Code section 39-71-119, defining an "eligible injury." Tocco, 714 P.2d at 163-64. The Montana statute defined an "eligible injury," in part, as "a tangible happening of a traumatic nature from an unexpected cause or unusual strain resulting in" certain types of harm. Id. (quoting Mont. Code § 39-71-119).

Iowa workers' compensation statute, by comparison, doesn't contain any language stating that injuries must result from an "unexpected cause or unusual strain." Iowa Code § 85.3(1). The relevant part of Iowa's statute to which we applied the "unusual strain" test in Brown simply asks whether Tripp's injury "ar[ose] out of and in the course of employment." Id. On that inquiry, the evidence was unrebutted (from the testifying doctors, Tripp's husband, and Tripp herself) that her PTSD arose directly from her handling of the screaming 911 call and the reports about the infant's maiming that immediately followed it and that Tripp answered the call in the course of her work as an emergency dispatcher for the SECC.

Focusing on the employee's own job in determining an "unexpected strain" places workers routinely tasked with addressing traumatic incidents, such as emergency dispatchers, paramedics, police officers, and firefighters, in a disfavored position as compared with other workers. They would bear a burden to prove hyper-unexpected causes and hyper-unusual strains—some extraordinary species of traumatic event, above and beyond the perilous events that they regularly confront—to qualify for benefits that those in less hazardous professions receive by meeting a far lower bar. Yet nothing in the language of Brown—nor, more importantly, in the text of section 85.3(1)—makes the "unexpectedness" or "unusualness" of the traumatic event dependent on the employee's own job duties. We thus hold that the district court erred in its interpretation of the statute in ruling otherwise.

This holding aligns with our existing workers' compensation law. If a police officer, for instance, is physically injured in a crash while pursuing a suspect in a high-speed chase, her injury ordinarily would be compensable despite the fact that police officers often pursue dangerous, fleeing suspects. But if an officer with a pre-existing heart condition has a heart attack on the job, the officer must still prove "that the injury arose out of the employment." P.D.S.I. v. Peterson, 685 N.W.2d 627, 630 (Iowa 2004). Applying our mental injury cases as we do today treats mental injuries in a similar fashion. For mental injuries "based on a manifest happening of a sudden traumatic nature from an unexpected cause or unusual strain" legal causation is established without regard to the regular duties of the particular employee or other employees in similar positions. See Brown, 641 N.W.2d at 728-29. But for mental injuries that might result from a combination of work-and non-work-related factors, the claimant must prove both legal and medical causation. See Peterson, 685 N.W.2d at 630; Dunlavey, 526 N.W.2d at 856-57.

The dissent never cites to, let alone analyzes, the actual text of the statute on which this case turns. The dissent's preferred application of the statute is premised on a fear that, unless courts require emergency responders to prove hyper-unusual work events caused their PTSD, emergency responders will make (and reap the benefits of) fraudulent PTSD claims. The dissent recites, for instance, that our causation test in Dunlavey for mental-mental injuries sought to address "difficulties in the evaluation of psychological injuries, such as the ease with which such claims may be feigned and the difficulty with which fraudulent claims can be detected." (Quoting Dunlavey, 526 N.W.2d at 855.) The dissent refers to our choice of the causation test in Dunlavey as "mindful" of an argument "that once 'mental/mental' claims are deemed compensable, employees will increasingly make fraudulent claims which the courts will not be able to detect and which will ultimately force employers out of business." (Quoting id. at 856.) Stated in its purest form, the dissent believes that its approach to proving the unusualness of the PTSD-causing event will prevent "fraudulent claims that are difficult to disprove."

On this subject, the dissent fights a battle that the SECC doesn't. The SECC doesn't claim that Tripp's PTSD diagnosis is "fraudulent" or unproven, or that it wasn't causally connected to Tripp's employment. No party in this appeal disputes that the 911 call in fact caused Tripp's PTSD. There is no claim of fraud, and there is no question of causation. The dissent instead presents a legislative policy rationale that it then superimposes on the text of the statute to support its interpretation. "Presumably," the dissent writes, "the legislature was unwilling to open the floodgates to mental injury claims as they are difficult to disprove and increase insurance costs while inhibiting job creation." Yet no hint of any of the things that the dissent "presumes" here are found anywhere in the statute or in this record.

Lest we lose sight of the polestar for our legal analysis in this case, we must interpret our own causation test in harmony with the words of the workers' compensation statute. The role of this court is to apply the words "of a statute as written." In re Marshall, 805 N.W.2d 145, 160 (Iowa 2011). "[W]e may not—under the guise of statutory construction—enlarge or otherwise change the terms of a statute as the legislature adopted it." State v. Miller, 590 N.W.2d 45, 47 (Iowa 1999). For us to interpret the statute to achieve some policy objective found nowhere in the statute's language—to presume the statute requires a higher standard of proof for PTSD based on fears of fraud—invades a sphere reserved for the legislature. See In re Est. of Gist, 763 N.W.2d 561, 567-68 (Iowa 2009).

The existence of any system of insurance, including workers' compensation, brings with it the potential for abuse. But the solution to this problem resides in the truth-seeking function of the adversary process, in which the trier of fact "considers expert testimony with an eye toward the concern that the claimant may be malingering, exaggerating his or her injuries, or attempting to claim an injury unrelated to employment." Travis J. Foels, Rescuing the Rescuer: Reforming How Florida's Workers' Compensation Law Treats Mental Injury of First Responders, 69 Fla. L. Rev. 1409, 1463 (2017). The workers' compensation system "already depend[s] on triers of fact to detect and weed out fraudulent or illegitimate claims." Id. Our court thus shouldn't presume it needs to cure some perceived legislative inattention by foreclosing recovery for a class of injuries that might otherwise qualify under the statute. "Our task is to interpret the statute, not improve it." Brakke v. Iowa Dep't of Nat. Res., 897 N.W.2d 522, 541 (Iowa 2017).

The dissent relies heavily on Moon v. Board of Trustees of Municipal Fire & Police Retirement System of Iowa, in which we applied Dunlavey's causation test to a disability claim by a police officer seeking benefits under Iowa Code chapter 411. 548 N.W.2d 565, 568 (Iowa 1996). In that case, an officer became permanently disabled after developing a panic disorder and agoraphobia after a confrontation with an armed robbery suspect and the suicide of a fellow officer. Id. at 567. We denied benefits under the Dunlavey test because the disabled officer failed to establish that these incidents were "more than the day-to-day stresses commonly associated with police departments," citing to testimony from another officer that "[t]here's a lot of stress associated with the job" and similar testimony from other officers. Id. at 569-70. But Moon, and another case the dissent recites, City of Cedar Rapids v. Board of Trustees of Municipal Fire & Police Retirement System of Iowa, 572 N.W.2d 919 (Iowa 1998), offer little of substance to our analysis in light of Brown's later reconstruction of the causation standard for "readily identifiable" events causing mental injury, as in this case.

Workers' compensation statutes are generally unique to each state, but several courts in other jurisdictions, interpreting statutes similar to Iowa's, have likewise held that purely mental injuries are compensable under an objective standard when the injury is caused by a readily-identifiable or directly-traceable event. For instance, the Oregon Supreme Court held a claimant's mental injury was compensable because his injury resulted from "actual stress conditions at work when viewed objectively." McGarrah v. State Accident Ins. Fund Corp., 296 Ore. 145, 675 P.2d 159, 172 (Or. 1983). Oregon's statute defined a compensable "occupational disease" as "[a]ny disease or infection which arises out of and in the scope of the employment, and to which an employee is not ordinarily subjected or exposed other than during a period of regular actual employment therein." Id. at 169 (quoting Or. Rev. Stat. § 656.802).

The Arizona Supreme Court permitted recovery for an officer who developed PTSD after a shootout with a gunman during a welfare check. France v. Indus. Comm'n of Ariz., 250 Ariz. 487, 481 P.3d 1162, 1163, 1167 (Ariz. 2021). The court rejected the employer's claim that the officer needed to "prove that the injury-causing event was outside the scope of his assigned job duties" because under that standard "a deputy who suffers mental injuries caused by a gunfight, regardless of the circumstances, could never receive compensation because such an incident might possibly occur in the line of duty." Id. The court emphasized that its holding was "limited to mental injuries arising from a specific work-related incident" and distinguished cases involving "gradual injuries resulting from ordinary stresses and strains of the work regimen." Id.

The Appellate Court of Illinois approved benefits for a police officer after he developed PTSD following a standoff with someone he believed to be wielding a gun. Diaz v. Ill. Workers' Comp. Comm'n, 2013 IL App (2d) 120294WC, 989 N.E.2d 233, 235-36, 370 Ill. Dec. 845 (Ill. App. Ct. 2013). The court rejected the commission's conclusion that the officer couldn't "recover because the traumatic incident was not an uncommon event of significantly greater proportion than what he would otherwise have been subjected to in the normal course of his employment as a police officer." Id. at 241-42. Such a standard, the court noted, would make it "virtually impossible for police officers or others involved in dangerous occupations to qualify for a mental-mental claim." Id. at 242. The court distinguished the incident from "a gradually developing mental disability" and found the appropriate standard for "whether a worker has suffered the type of emotional shock sufficient to warrant recovery should be determined by an objective, reasonable-person standard, rather than a subjective standard that takes into account the claimant's occupation and training." Id. at 241-42.

The Supreme Court of Louisiana likewise found that for "cases involving such readily identifiable, unusual and dramatic events," the claimant must be compensated "when there is sufficient evidence that the sudden event caused the disabling mental condition." Sparks v. Tulane Med. Ctr. Hosp. & Clinic, 546 So. 2d 138, 147 (La. 1989) (emphasis added). But "an employee's general allegation that he is unable to work due to stress or tension caused by working conditions," according to the court, "would not give rise to a compensable claim." Id.

The national landscape shows increasing support for laws that ensure emergency responders have an opportunity to receive workers' compensation benefits for PTSD. "A vigorous trend is for states to make exceptions, within exclusionary laws, for first responders via the legislative 'presumption of causation' device." David B. Torrey & Donald T. DeCarlo, Mental Stress Causing Mental Disability Under Workers' Compensation Laws: A Short History, the Competing Arguments, and A 2021 Inventory, 56 Tort Trial & Ins. Prac. L.J. 91, 134 (2021). The National Council on Compensation Insurance, "which carefully monitors proposed bills and enactments on this topic," identified PTSD bills ensuring eligibility for emergency responders as "the top trending issue for 2019." Id. at 134-35, 173 (showing seventeen states with enacted legislation at the time of the article's publication and another seventeen states with some kind of proposed legislation).

What's more, making it harder for emergency responders to receive workers' compensation for mental injuries would rest on a dubious assumption: that emergency responders have, or should have, some natural or acquired immunity to psychological injuries that might result from participating in traumatic human experiences. Few people, if any, could know if they possess such an immunity going in. And none would know for certain that they'd be able to maintain it. Tripp's PTSD diagnosis, by all accounts, is a case in point: she was always able to deal with the trauma of the job for sixteen years until, one horrific day, she wasn't.

Setting different baselines for proving workers' compensation eligibility—one for emergency responders and one for everyone else—further presupposes that emergency responders agreed to assume the risk of suffering psychological injuries simply by accepting the job. The legal basis for this "assumption of risk" notion is unclear; it's certainly found nowhere in this record. In any event, our workers' compensation statute embodies a "no fault" system: employers are not liable for their negligence in causing a workplace injury and workers are not subject to a setoff in benefits for their own conduct that might have contributed to their injury. See Peterson, 685 N.W.2d at 635. Workers thus can't be denied benefits based on a common law "assumption of risk" defense to an injury claim. Hawk v. Jim Hawk Chevrolet-Buick, Inc., 282 N.W.2d 84, 91 (Iowa 1979) (en banc).

Our workers' compensation statute doesn't impose a higher burden on workers with jobs that involve frequent brushes with traumatic events than workers in other occupations. Workers' compensation, it bears repeating, is a statutory creation, with eligibility for benefits determined by what the statute provides. See McSpadden v. Big Ben Coal Co., 288 N.W.2d 181, 188 (Iowa 1980). We find it—as we must—not for us to create favored and disfavored classifications among occupations or injuries when the legislature has made no such classifications in its statute. Allowing emergency responders to receive workers' compensation for their proven mental injuries, without imposing some heightened evidentiary hurdle absent in our statute, merely provides them with the compensation to which they're legally entitled.

IV.

When a purely mental injury is traceable to a readily identifiable work event, the claimant proves legal causation by meeting the test that we set forth in Brown by analyzing the unexpected or unusual nature of the injury-inducing event without regard to the claimant's own particular duties. Tripp satisfied the requirements for medical and legal causation. We thus reverse the decision of the district court and remand the case to the workers' compensation commissioner to determine the extent of Tripp's disability.

REVERSED AND REMANDED.

Christensen, C.J., and Appel and Oxley, JJ., join this opinion. Christensen, C.J., files a concurring opinion. Waterman, J., files a dissenting opinion, in which Mansfield and McDonald, JJ., join.