The 19th launch of the Falcon 9 vehicle from SpaceX Sunday morning at 10:21AM EST resulted in the rocket exploding around 2:20 seconds into flight. This would be just before the time the first stage would separate from the second stage. Unclear whether the rocket exploded or something went wrong and the Flight Safety Officer exploded the vehicle. Did look like there was massive gas coming out between where the first and second stages meet up as you can see for yourself. Almost looks like the second stage ignited prematurely.
From James Dean (Florida Today): This raises huge questions for the ISS program, following on the heels of a Russian Progress resupply ship's failure in April. Before that, last October, Orbital Sciences Antares rocket failed. So every major resupply system has now failed in the last year.
All programs are now in suspension awaiting determination of their failure causes.
Via James Dean: Statement from the Air Force's 45th Space Wing:
SPACE X CRS-7 LAUNCH ANOMALY OCCURS 148 SECONDS INTO FLIGHT
CAPE CANAVERAL AIR FORCE STATION, Fla. - After a successful liftoff from the Eastern Range, 45th Space Wing, Space X and NASA officials experienced an anomaly of the Falcon 9 CRS-7 mission June 28 at approximately 148 seconds into flight.
Elon Musk via Twitter: There was an overpressure event in the upper stage liquid oxygen tank. Data suggests counterintuitive cause. That's all we can say with confidence right now. Will have more to say following a thorough fault tree analysis.