A bird strike on the HH-60G Pave Hawk at 110ft at 126mph caused the crash of a helicopter on a moonlight training mission on the Norfolk Wildlife Trust reserve, killing staff Sgt Afton Ponce, Capt Christopher Stover, Technical Sgt Dale Matthews and Capt Sean Ruane.
The crew was confirmed dead at the scene. The investigation has begun, and there is a fund opened for them.
A number of twelve pound geese struck the helicopter after the flock flew up alarmed by the noise.
The USAF chopper was flying out of Lakenheath in Suffolk.