Offnominal

Elon Musk had some new information quoted over at his brother’s blog regarding yesterday’s failure

However, at T 25s, a fuel leak of currently unknown origin caused a fire around the top of the main engine that cut into the first stage helium pneumatic system. On high resolution imagery, the fire is clearly visible within seconds after liftoff. Once the pneumatic pressure decayed below a critical value, the spring return safety function of the pre-valves forced them closed, shutting down the main engine at T 29s.

It does not appear as though the first stage insulation played a negative role, nor are any other vehicle anomalies apparent from either the telemetry or imaging. Falcon was executing perfectly on all fronts until fire impaired the first stage pneumatic system.