The failure was suspected to be due to a turbopump bearing that came loose, causing the liquid oxygen pump to stop. The abrupt loss of thrust caused the Thor to lose attitude control and pitch downward, which caused the LOX tank to rupture from aerodynamic loads and resulting in complete destruction of the launch vehicle. Erratic telemetry signals were received from the payload and upper stages for 123 seconds after the explosion, and the upper stages were tracked to impact in the ocean.