The concurrent cause rule basically holds that if two or moreevents cause a loss, with one being excluded under the policy termsand the other(s) being covered, the policy should provide coveragefor the loss.

As discussed in Davidson Hotel Co. v. St. Paul Fire and MarineInsurance Co., 136 F. Supp. 2d 901 (2001), this ruleallows for coverage “where the loss is essentially caused by aninsured peril with the contribution of an excluded peril merely aspart of a chain of events leading to the loss.” The thinking behindthis ruling and other concurrent causation cases is that the causeof loss that is not excluded caused damage to the insured'sproperty in one way or another, so the property coverage form mustpay for the loss.

As a modification of the concurrent cause rule, some courtsdeveloped the efficient proximate cause rule. Couch onInsurance states that this rule permits recovery for a losscaused by both a covered cause of loss and an excluded cause ofloss if the covered cause was the efficient proximate cause of theloss. That is, the covered cause set the other causes in motionthat, in an unbroken sequence, produced the result for whichrecovery is sought. (Note that courts have not reached a consensuson the precise definition of efficient proximate cause, althoughmost jurisdictions do require an analysis of the events todetermine the nearness or proximity of the cause to theeffect.)