A civilian helicopter with four Norwegians on board has crashed into iced-over water in the Oslo fjord off southeastern Norway and divers searched for survivors, rescue workers said.
The helicopter went down in foggy afternoon weather 500 feet off Horten, a town an hour south of Oslo, Norway Central Rescue spokesman Einar Knudsen said.
Knudsen said divers had not yet found the wreckage of the helicopter and, though hampered by murky water and strong undercurrents, were still "searching for survivors".
However, he acknowledged that the helicopter was "probably" resting on the sea floor in 39 F water about 66 feet deep.
An unnamed Norwegian company had hired two Robinson R44 model helicopters owned by Midtnorsk Helicopter Service to ferry five employees from Tonsberg 60 miles north to Oslo when one went down, Midtnorsk spokesman John-Erik Sogn said.
The pilot of the second helicopter, which landed safely in Horten, saw "the other one suddenly started to spin in mid-air -- at 800 feet above the water -- before it went down," Sogn told The Associated Press.
He said that Midtnorsk, which operates sightseeing trips and charter flights in Norway, services its helicopters after every 50 hours in the air and that the company has never experienced a crash like this before.
According to Norway's Accident Investigation Board, there have been nine accidents in Norway involving the Robinson R44 helicopter since 1998, none of them fatal.