Police have named the four dead oil workers in the Shetland helicopter crash - as nearly all Super Puma aircraft were grounded.
The victims are: Duncan Munro, 46, from Bishop Auckland; Sarah Darnley, 45, from Elgin; Gary McCrossan , 59, from Inverness; and George Allison, 57, from Winchester.
The Super Puma L2 went down at approximately 6.27pm on Friday, around two miles west of Sumburgh airport as it was returning to Shetland from the Borgsten Dolphin platform.
The helicopter was carrying 16 workers and two crew.
At a meeting of the Helicopter Safety Steering Group, offshore companies and unions agreed to suspend commercial flights by all models of Super Puma until at least next Wednesday.
Search and rescue flights will be unaffected.
"The bodies of three people have been recovered and work is underway to recover the body of the fourth person," Police Scotland said in a statement.
The body of the fourth victim is understood to be in the wreckage of the aircraft.
All the families have been informed.
A statement from Mr Munro's family said: "Duncan was a fabulous father to Katy aged 12 and a devoted husband to Penny. He was a loving brother and a good friend and colleague to many.
"He will be sadly missed by everyone that knew him and his death will leave a large void in a lot of people’s lives.
"His family would like to thank everyone for the kindness and support given since they received the tragic news, they would also like to pass on their sincere condolences to the other families who have also lost loved ones in this tragic incident."
A search operation involving coastguard, police, RAF and local lifeboats was able to rescue 14 people from the sea, including the two crew. They were taken to Gilbert Bain Hospital in Lerwick.
"Five were discharged and nine detained overnight either for observation or suffering from exposure," the police statement said.
The helicopter is reported to be in several pieces but the wreckage has now been secured by the RNLI (Royal National Lifeboat Institution).
Helicopter operator CHC, which operates in 30 countries, said on its website that it was temporarily suspending all Super Puma L2 flights worldwide as a precaution.
It has also suspended flights in Aberdeen "as a mark of respect".
Amanda Smith, the mother of one of the workers, Sam Smith, said that her son had telephoned her from hospital after suffering cuts in the crash.
She told Sky News: "He said it seemed to lose power and there was no time to brace, they just dropped into the sea.
"He was by the window so he was able to escape that way as it rolled over.
"He said he had come off better than a lot of people. It didn't seem real, I would say two hours later it's just beginning to sink in."
CHC said it was flying for French oil company Total and that the aircraft had lost communication as it approached the airport on the southern tip of Shetland's main island.
The four people who died were working for Total through contractor organisations.
A CHC spokesman said: "The aircraft was on approach to Sumburgh Airport at approximately 6.20pm when contact was lost with air traffic control."
Mark Abbey, regional director for CHC, expressed his "heartfelt sympathies to all those involved" but said the company would not be speculating about the cause of the crash.
Investigators from the Department for Transport's Air Accidents Investigation Branch are looking into the incident.
The helicopter was upside down in the water when rescuers arrived, said Sky's James Matthews in Aberdeen.
"At least three of the four who died had trouble getting out of the wreckage. One body remains in there this morning," said Matthews.
The survivors were aided by waterproof immersion suits that helped keep them afloat and warm in the North Sea.
The tide - which was heading towards the land - also helped survivors.
Jim Nicholson, RNLI rescue co-ordinator, said: "There appears to have been a catastrophic loss of power which meant the helicopter suddenly dropped into the sea without any opportunity to make a controlled landing."
Last year, two Super Puma helicopters ditched in the North Sea only six months apart.
All passengers and crew were rescued in both incidents, which were found to be caused by gearbox problems.
However, the latest incident marks the fourth in four years involving Super Puma aircraft.
In April 2009, 16 people died when a helicopter returning from BP's Miller platform crashed 11 miles from Peterhead after a "catastrophic failure" in part of its main gearbox.
The Unite union's Scottish Secretary, Pat Rafferty, said the safety record was "unacceptable" and called on the oil and gas industry to use "every means at their disposal to demonstrate that its fleet is fit for purpose".
Bob Crow, head of the RMT union, said he expected an "outpouring of anger" after the latest incident.
"The entire Super Puma fleet must remain grounded until the causes of this latest event are established," said Mr Crow.
:: CHC has set up a helpline for concerned relatives on 01224 296 866.