Tributes have been paid online to o ne of four US servicemen thought to have been killed in a military helicopter crash on the north Norfolk coast.
Captain Sean Ruane is said to have been an experienced pilot, but it remains unclear whether he was at the controls of the Pave Hawk helicopter that came down on a marsh near Cley-next-the-Sea last night.
Based at RAF Lakenheath with US Airforce 48th Fighter Wing, he leaves behind wife Rachel and their young son Liam.
His cousin Brian Meyer tweeted: "My cousin died in a helicopter crash tonight. Pretty tore up about this.
"Everyone: thanks for all the kindness. I'll pass it along to his wife and child when we see each other soon."
Mateo Spencer wrote: " Rest in Peace to my friend Sean Ruane, aircraft pilot downed in a crash in England today."
Mrs Ruane described her husband as "outgoing and dedicated to others" on a wedding website at the time of their marriage in July 2011.
She said: "Sean is a pilot in the Airforce and he flies Pavehawk Rescue Helicopters.
"I am so proud of what he does and that he has chosen to serve our country.
"Sean is outgoing and loves to spend time with his friends and family. His dedication to others is one of his best attributes. There are very few men like him.
"I consider myself very blessed because Sean is my perfect match and we have so much to look forward to."
Authorities have said that the bodies of those killed in the crash are unlikely to be recovered until tomorrow.
Air accident, RAF and US investigators have spent the day at the scene of the tragedy, where debris is believed to have been strewn across an area the size of a football pitch.
A statement from 48th Fighter Wing said that the helicopter was performing a low-level training mission along the coast when the crash took place.
The investigation is being hampered because it was carrying munitions, meaning that bullets are scattered around the scene, investigators said.
Norfolk Police confirmed paramedics were not needed to treat those inside the helicopter, suggesting they died on impact or soon after.
Paying tribute to them, Colonel Kyle Robinson, 48th Fighter Wing commander, said: "The loss of our Liberty Wing brethren is felt deeply across RAF Lakenheath.
"I can only imagine the hurt and sorrow felt by the family and friends of these airmen. You are in our hearts and minds.
"We're already feeling a great sense of support from across the air force and from our UK neighbours as we go through this difficult period.
"Thank you for keeping our airmen and their families in your thoughts and prayers."
A 400-metre police cordon is expected to remain in place at the scene until Monday and the public have been asked to stay away.
Investigators are aware of how much ammunition was on board and are attempting to account for it all.
Military investigators from the US and UK are expected to work together to establish exactly what happened once the police involvement is over.
Speaking in nearby Salthouse this afternoon, Chief Superintendent Bob Scully said: "You would be very much mistaken if you thought this would be a quick process.
"It all hinges on our ability to establish what happened and the removal of the casualties, who are sadly deceased, could disrupt the evidence so this must be done methodically step-by-step."
A derivative of the more famous Black Hawk helicopter, the Pave Hawk gets its name from the Pave acronym standing for Precision Avionics Vectoring Equipment.
They are used for combat search and rescue, mainly to recover downed aircrew or other isolated personnel in theatres of war.
They have a four-man crew and can carry up to 12 troops. Typically, training flights would replicate as closely as possible real missions which would mean weapons and ammunition would be carried.