(Bloomberg) -- Hurricane Irma’s westward shift willprobably inflict heightened damage on people and businesses unableto adjust to its new path in time, while the storm fuels floods that many insurance policies don’tcover.

Along Florida’s west coast — now in the direct path of thestorm — many residents thought they would avoid the worst ofit, and then found themselves with too little time to fullyprepare, according to Duncan Ellis, the U.S. property practiceleader at Marsh & McLennanCos.’ main brokerage unit.

Turn to left caused a scramble

Such was the scene near the waterfront in Tampa as the winds beganto pick up. On Harbour Island late Saturday, condo resident MontyGawel said he was only able to fill three sandbags, using dirt froma planter. While the 50-year-old intended to stay, a number of hisneighbors were fleeing.

Nearby, some shops lining Garrison Channel were protected onlyby a single line of sandbags, just one sack high. Their glasswindows and doors remained uncovered.

“Most people expected it to impact the east coast rather thanthe west coast,” said Ellis. “It took a turn to the left, andthat’s caused a bit of a scramble in getting properties ready forthe storm and evacuations.”

Early loss estimates

Total damage from Irma could reach about $49 billion, with $19billion picked up by private insurers, according to Enki Researchrisk modeler Chuck Watson. That’s dramatically lower than earlierpredictions after the storm’s harshest winds began to slow.

But within such broad figures, insurers are starting to sketchout damage trends with big implications for individual customers.Those will continue to unfold as Irma progresses.

Even after the westward shift, larger, commercial clients aretypically well prepared, and even able to help those who aren’t,Ellis said. “If you’re a big-box store selling 2x4s, flashlights,plywood and all of that, you stay open as long as you can,” hesaid.

Lack of storm surge coverage

Aside from catching some people underprepared, the new trajectoryis threatening to hit areas like Tampa with storm surge, which isparticularly costly. Many residential policies cover rain, but notflooding from open water. That means affected policyholders mayfind themselves waiting for longer for checks as claims areevaluated, or ultimately paying out of pocket to make repairs.

Related: Hurricane deductibles: How much do homeownersknow?

“Tampa Bay is an area that insurance underwriters have beenconcerned about for a very long time,” said Rick Miller, the head of the U.S. property practice atAon Plc. “There’s a lot in harm’s way, and it’sheavily exposed given it’s low-lying state.”

Irma is adding to pressure on insurers after Hurricane Harveystruck Texas last month.

Florida's residential market unique

Florida’s residential property insurance market isunique. Many of the large, national carriers began scalingback from the state after Hurricane Andrew in 1992, and retreated furtherafter a costly spate of storms in 2004 and 2005.

Today, the top underwriters are a group of smaller, lesser-knowncompanies — including Universal Insurance Holdings Inc. and FederatedNational Holding Co. — as well as a state-run entitycalled Citizens PropertyInsurance Corp.

Copyright 2018 Bloomberg. All rightsreserved. This material may not be published, broadcast, rewritten,or redistributed.