OSLO: A helicopter ferrying passengers from a Norwegian oil platform crashed in the North Sea on Friday, killing at least 11 of the 13 people on board, rescue officials said. The 11 passengers and two crew on the flight from the Gullfaks B oil platform, operated by Statoil, were all Norwegian except for one British and one Italian national, according to the Rescue Coordination Centre for Southern Norway. “The helicopter is completely destroyed,” it said. After several hours searching for survivors, 11 bodies were found and the remaining two people were presumed dead. Several witnesses told Norwegian media they saw the rotor separate from the helicopter while still in the air. “While I looked up, the rotor loosened and disappeared towards the north,” John Atle Sekkingstad told the website of local paper Bergens Tidende. “After that, the helicopter turned north and I saw fire at the top of the helicopter, where the rotor had been attached. It caught fire before it crashed.” The main body of the aircraft was lying under water, while its rotor was found on a rocky outcrop 200-300 metres (yards) away, state broadcaster NRK said, quoting the rescue centre. Plumes of smoke rose from the scene, a stretch of sea with many small islands. Pieces of red debris could be seen on the rocks, TV pictures showed. Another witness, oil worker Chris Andersen, told NRK: “I saw the rotor separate …. It was horrible. There was a huge explosion that you could physically feel. You felt the vibrations.” Norway’s king and the prime minister expressed their condolences to the families of the victims.