Twenty passengers were injured, including two women who were airlifted to hospital, when a single-decker bus spun out of control and plunged five metres down a slope on Lantau yesterday. Some of the injured said they could have been killed had the bus not been stopped by a tree halfway down the 10-metre slope. The crash happened on the Keung Shan Road near the Shek Pik Reservoir shortly before 10am. One passenger said: 'The bus broke through one large group of trees and then a second group of trees before coming to a stop. If it had carried on to the bottom, it could have been a lot worse.' He said several passengers who were either trapped or too hurt to free themselves, needed to be rescued. He said: 'I could see that two women had passed out. Passengers tried to pull out those with more serious injuries.' Some passengers said after the crash that they believed the accident had been caused by the bus skidding on a slippery road surface. Fire and ambulances arrived five minutes after the accident. The two women, aged 47 and 53, who sustained more serious injuries, and a third girl were airlifted by government helicopters to Tuen Mun Hospital. Both were in stable condition last night, with the girl later released. Seven injured passengers, aged between five and 51, were sent to Princess Margaret Hospital. Most suffered leg, arm and head injuries. Ten others with slight injuries were treated at the crash site. The bus driver, 50, was not injured. He passed a breathalyser test. Firemen and engineers were yesterday trying to stabilise the slope and recover the wreckage. A tram driver was seriously injured and nine passengers, including a seven-year-old girl, were slightly hurt in a three-vehicle pile-up involving two trams and a double-decker bus in North Point at 6pm yesterday. Police said the accident happened when the bus driver veered on to the tram track in an attempt to avoid congestion on King's Road. One tram went off the track and it smashed into another tram travelling in the opposite direction. The driver of the first tram, 59, was admitted to Eastern Hospital in a stable condition while nine passengers were treated in hospital and later released.