Toby Melville / Reuters
A Pave Hawk helicopter, military personnel and emergency services attend the scene where another helicopter crashed near the village of Cley in Norfolk, eastern England.
Four American airmen were killed when a U.S. military helicopter carrying live ammunition crashed into a nature reserve on the east coast of England on Tuesday, spreading debris including "hazardous" bullets across an area the size of a soccer field, police said.
The Air Force HH-60 Pave-Hawk chopper — a modified version of the Army's Black Hawk — was practicing flying at low altitudes when it went down, the U.S. officials said. It was assigned to RAF Lakenheath, the British base that is also home to the U.S. Air Force's 48th Fighter Wing.
The airmen were named as Capt. Christopher S. Stover, Capt. Sean M. Ruane, Tech. Sgt. Dale E. Mathews, and Staff Sgt. Afton M. Ponce.
"The actual crash site I would describe as an area of debris on difficult terrain on the marsh about the size of a football field,” Chief Bob Scully of Norfolk Police said early Wednesday, adding that the area had been cordoned off from locals because the crashed aircraft had strewn live ammunition across the crash site on impact.
"Bullets are scattered about the area of the site," he said. "So that is hazardous to members of the public."
He added that another helicopter had been taking part in the training mission.
“Because they were both airborne the most immediate aircraft to provide assistance or be available at the scene was the other aircraft,” Scully said.
He added that at the present time British police had jurisdiction over the investigation because the crash happened on English soil.
"At the present time the police on behalf of her majesty’s coroner are responsible for conducting an investigation into deaths that have occurred here in the U.K.," he said. "Once we are satisfied and the coroner is satisfied we will then pass the management of the scene to the air investigation branches of the U.K. and U.S, military.
“They will carry out a more technical investigation that may last for some considerable time,” he added.
Police have been assisted by investigators from both Britain's Royal Air Force (RAF) and the United States Air Force.
“(We) have been conducting a full scene assessment in difficult terrain and that has allowed us to plan for the activities today which will involve further close examination and scene examination and preserving evidence from the crash site,” he said.
The bodies were removed from the scene early Thursday after the British coroner conducted a daylight assessment of the scene.
The commander of the 48th Fighter Wing, Colonel Kyle Robinson paid tribute to his colleagues and thanked the British people for their support.
"They have made the ultimate sacrifice while training to save the lives of others," he said, adding that as a husband and father he could not imagine the heartbreak the families were experiencing.
"I speak for the entire wing when I say we're thinking of you, we're here for you and we're praying for you," he said.
Although the base is owned by the RAF, it has been used by the United States Air Force for over 50 years.
NBC News' Jim Miklaszewski, Courtney Kube and Marc Smith of NBC News contributed to this report.
This story was originally published on Wed Jan 8, 2014 4:17 AM EST