Tyre fire?
Excuse my engineering ignorance here, but is it possible that missing heat shields near the wheel bay could have caused heat build up in that area to a point where the tyre could have caught fire?
Just the sequence of the events below posted by "ORAC" has me intrigued.
08:53
20 to 30 degree rise in temperature in left wheel well over 5 minutes.
08:54 (Eastern California & Western Nevada)
Mid-fuselage bond line (bond between fuselage and top of wing on the port side) has a 60+ degree temperature rise over 5 minutes. Starboard side is nominal at 15+. Inside of fuselage wall the temperature is nominal.
8:56 a.m.
Sensors detect rise in temperature and pressure in tires on the shuttle's left-side landing gear.
8:58 a.m.
Data is lost from three temperature sensors embedded in the shuttle's left wing.