According to news reports, the July C-17 crash that killed four crewmembers shortly after takeoff in Alaska was caused by pilot error.  The report’s press release and a video of the C-17 takeoff (up to just prior to impact), are available on the PACAF website.  (The video has already made it to YouTube as well.)

According to the release, 

The accident investigation board found clear and convincing evidence the cause of the mishap was pilot error… The pilot placed the aircraft outside established flight parameters and capabilities… The pilot aggressively flew the aircraft in a manner inconsistent with established flight procedures, resulting in a stall. The pilot failed to take required stall recovery actions. Furthermore… the co-pilot and safety observer failed to recognize or address the developing dangerous situation. As a result, the C-17 stalled at an attitude and altitude from which recovery to controlled flight was impossible.