SpaceX revealed early findings of its analyses Monday following weeks of intense evaluations and testing. The company said in part:
“Preliminary analysis suggests the overpressure event in the upper stage liquid oxygen tank was initiated by a flawed piece of support hardware (a “strut”) inside the second stage. Several hundred struts fly on every Falcon 9 vehicle, with a cumulative flight history of several thousand. The strut that we believe failed was designed and material certified to handle 10,000 lbs of force, but failed at 2,000 lbs, a five-fold difference. Detailed close-out photos of stage construction show no visible flaws or damage of any kind.”
To read the complete statement from SpaceX, go to http://www.spacex.com/news/2015/07/20/crs-7-investigation-update