The rumor I heard on Chicago am radio
Assault Vehicle Catches Fire on Highway 24
An FBI armored assault vehicle caught fire on an East Bay freeway Wednesday morning, setting off several small explosions as the weapons inside burned.
The FBI swat team was heading eastbound on Highway 24 to a training exercise, when a broken coolant line apparently sparked the flames.
"The agents managed to get out of the car and tried to hold traffic," said Sgt. Norm Roy of the California Highway Patrol. "However, their personal weapons were inside the vehicle and some of the rounds were going off."
The CHP said the armor plating on the swat vehicle kept the exploding ammunition contained and away from the public. No one was hurt.
http://cbs5.com/news/local/2004/05/26/Assault_Vehicle_Catches_Fire_on_Highway_24.html