Hurricane Ian caused billions of damage and destroyed lives, but few expected electric vehicles to catch fire.

But that’s exactly what happened.

In the days after Hurricane Ian, the saltwater flooding in coastal areas caused the lithium-ion batteries in electric vehicles to burn.

For example, firefighters in Naples had to extinguish six flames in EVs submerged in seawater.

Heather Mazurkiewicz, a spokesman for the fire service, said firefighters needed “thousands and thousands” of gallons of water to put out the EV fires — far more than what a typical gas car fire would require.

Worse, one of the EVs caught fire again, destroying two homes.

Related: This solar-powered Florida city was built to withstand hurricanes. Did it work?

Why EVs burn

Eric Wachsman, the director of Maryland’s Energy Institute, told CNBC that lithium-ion battery cells have electrodes placed closely together and filled with a flammable liquid electrolyte.

When the battery cells become damaged or malfunction, “this flammable liquid can get into what’s called a thermal runaway, where it just starts to boil, and that results in a fire,” Wachsman said.

For this reason, some companies, such as Tesla and Ford, are switching to lithium iron phosphate (LFP) batteries, which are much less flammable.

But that won’t stop the cars that already have a lithium-ion battery from catching fire.

Florida takes action

To protect first responders and firefighters, Jack Danielson, executive director of the National Highway Traffic Safety Administration, ordered those “not involved in immediate life-saving missions” to identify flooded electric vehicles with lithium-ion batteries and send them “at least 50 feet” away from other structures, vehicles and combustible materials.

Senator Rick Scott also wrote a letter to US Secretary of Transportation, Pete Buttigieg, D, calling for action.

“This emerging threat has forced local fire departments to divert resources away from hurricane recovery to control and contain these dangerous fires,” Scott wrote. “It is alarming that even after the car fires are extinguished, they can flare up again in the blink of an eye.”

There are more than 95,000 registered EVs in Florida, the second highest number in the nation.