A British Airways jet carrying 152 people crash landed Thursday at Heathrow airport, tearing its underbelly, damaging its wings and skidding to a halt before emergency chutes deployed. All aboard escaped safely, but eight people were hurt. Fire trucks surrounded the Boeing 777, which had taken off from Beijing, after it landed early in the afternoon, spraying fire retardant foam around the aircraft. The plane's wheels appeared to collapse as it came down in the grass in front of the airport's southern runway, witness John Rowland told the British Broadcasting Corp. "It crashed into the runway, debris was flying everywhere, there was an enormous bang and it skidded sideways," he said. London Ambulance Service said eight people had been taken to a hospital with minor injuries. The accident at one of Heathrow's two runways occurred just before a plane carrying British Prime Minister Gordon Brown and a delegation of business leaders, including Virgin Chairman Richard Branson, was about to depart for China. The prime minister's plane was about (one kilometer) half a mile away. The crash forced Europe's busiest airport to temporarily halt departures and arrivals while emergency crews worked at the scene, causing massive delays. More than 200 flights were canceled -nearly a fifth of the days flights, airport operator BAA said. Planes were still able to take off and land on Heathrow's northern runway, air traffic control company Nats said. Some other flights were diverted to other airports. Nothing suggested the incident was terror-related, Scotland Yard said. The Air Accident Investigation Branch was investigating, British Airways Chief Executive Willie Walsh told reporters, adding that the airline did not want to speculate on the cause. Investigators will pore over the plane's flight data recorder, the cockpit voice recorder and maintenance records to determine what happened, officials said. Airline staff were looking after the passengers, Walsh said. It was the first crash involving the Boeing 777, a mainstay of many carriers' fleets, since the plane entered service in 1995, said Boeing spokeswoman Liz Verdier in Seattle. The Boeing 777, one of 42 in the BA fleet, was relatively new at 6-years-old, Walsh said, adding the pilot was one of BA's most experienced, with nearly 20 years with the company. Emergency workers surrounded the plane and firefighters sprayed fire retardant foam as a precaution as the 16-member crew evacuated passengers on inflatable chutes. Two of the plane's giant wheel units were ripped from the craft during the landing and could be seen on grass near the runway. The plane's engines were louder than normal, said Neil Jones, a witness and licensed pilot. "The aircraft was banking to the left and it was coming in very low over the surrounding houses," he said. Onboard, passenger Paul Venter said he noticed nothing strange until the aircraft was about to land. "The wheels came out and went for touchdown, and the next moment we just dropped. I couldn't tell you how far," he said. "I didn't speak to the pilot, but I saw him, and he looked very pale, but there was no communication in the cabin," Venter said. Passenger Jerome Ensinck told the BBC that he first thought the plane had made a hard landing. "When we hit the ground it was extremely rough," he said. "Then the emergency exits were opened and we were all told we should go through as quickly as possible, and the moment I was away from the plane I started to realize that the undercarriage was away, and we had missed the runway, Ensinck said. "Now I realize I've had a close call," he said. Robert Cullemore of Aviation Economics, a London-based aviation consultancy, said a pilot from a competing airline told him officials believed the cause of the accident was wind shear, a sudden gust of wind. "It can happen anytime anywhere and if it happens you just hope there is no airplane nearby," Cullemore said. He said the pilot kept the plane in the air long enough to prevent a disastrous outcome. "If it had landed 200 meters shorter than it did, it may have hit perimeter fence and obviously some other buildings and the car park, clearly we would be dealing with fatalities and obvious damage," Cullemore said. There are a few other possibilities, said Timothy Crowch, an aviation analyst with 35 years experience as a commercial pilot. The landing gear punched through both wings, indicating a "massive vertical impact." That suggests a total loss of engine power may have been the cause, he said "You're dealing with a premier airline with a safety record equal to the best, with aircraft only a few years old, this is phenomenally rare," Crowch said. Kieran Daly, editor of the Air Transport Intelligence Web site said the trouble seemed to occur in the flight's last few seconds. "It's clear the pilot did not warn the passengers that anything was going to happen and there is no evidence he made any emergency call on radio," he said. "It is very strange."