More than 3,500 rental cars were damaged or destroyed in a fire that burned across 15 acres near a Florida airport before being contained late Friday night.

The cars were in a grassy area that is used as an overflow lot by car rental companies servicing Southwest Florida International Airport.

Witnesses said they heard multiple small explosions and flames. Another 3,850 vehicles were undamaged, according to airport spokeswoman Vicki Moreland.

Multiple law enforcement agencies in Southwest Florida assisted in controlling the fire and managing roads.

Investigators are still trying to determine the cause of the fire.