Memorial service held for US Air Force victims of Norfolk helicopter crash US Air Force (USAF) Captains Christopher Stover and Sean Ruane, Technical Sergeant Dale Mathews, and Staff Sergeant Afton Ponce, were killed when the Pave Hawk helicopter they were onboard during a training mission crashed on marshland on the North Norfolk Coast. On Friday, body armour, rifles and dog tags belonging to each crew member were on display as their fellow military colleagues gathered at RAF Lakenheath, Suffolk, where they were based. The private service had been arranged to allow the military community to come together to recognise the tragedy. Tributes were read to each of the air crew members of the 56th Rescue Squadron in the base's Hangar Seven. A spokesman from RAF Lakenheath said: "Your continued thoughts and prayers are appreciated." Norfolk Police has handed the investigation over to the USAF as there was no evidence that the crash was a criminal matter. The USAF, supported by the Ministry of Defence, is to lead the investigation into the crash.