[tubebender]

Why would the brakes catch on fire. They were on level ground going very slow. I saw the firefighters inspecting the luggage compartment on the side of the bus and the area around it was severely burned. There could have been extra tanks in there, ala Valu-Jet...

[School Bus Driver]

The driver probably left the emergency brake on.

The brakes would not have caught fire under normal use.

(stop and go traffic, the driver gets tired, engages parking brake, forgets about it...)

[Steve_Seattle]

"Why would the brakes catch on fire. They were on level ground going very slow. I saw the firefighters inspecting the luggage compartment on the side of the bus and the area around it was severely burned."

I agree that the brakes-caught-fire theory sounds pretty weak. AS you seem to suggest, perhaps some flammable material was improperly stored in the luggage compartment, and caught fire in there. Then the compressed oxygen in the passengers' tanks could have caused secondary explosions. But the whole thing is too weird. As MHKING would say, "Just damn."