An unoccupied ambulance burst into flames and exploded while parked in front of an El Cajon, Calif. Mall Thursday afternoon, according to The San Diego Union-Tribune.
The ER Ambulance Service unit was at the Westfield Parkway Mall at 415 Parkway Plaza when the fire started shortly before 4 p.m.
The ambulance was fully engulfed in flames by the time firefighters arrived, city spokeswoman Monica Zech told the newspaper.
A representative from the Hearthland Fire Department, which responded to the blaze, told KNSD-TV that tanks inside the ambulance caused the explosion.
A witness told the news station that the EMTs tried to access the extinguisher inside, but couldn't reach it through the flames.
The cause of the fire is currently under investigation.