'Auntie Jiang' credits other passengers with saving her life and that of her young granddaughter by pushing them out the door in a rush to escape a mystery blaze that turned a Shanghai bus into a death trap. She told of grabbing the girl by the jacket and holding her in her arms as she battled towards the door. 'I embraced the child and the people behind me all of a sudden pushed me off the bus,' she said. She had been travelling from her home into the city when disaster struck near the bus terminus yesterday morning. 'The bus door had just opened. Suddenly I smelled a strange odour, then one seat in the bus burst into flames,' she said. Others weren't so lucky. One witness said those who couldn't escape were elderly. 'I saw three dead. One had no clothing left,' the witness said. Local media reported that at least one elderly woman had died. Witnesses gave conflicting accounts of what happened, deepening the mystery over the fire, which police said was caused by a passenger who had been carrying flammable materials. Some said there was an explosion, although others said they heard nothing. Some said the middle door of the bus was open to allow people to escape, while others claimed only the front door was open. But all agreed the fire was a terrible sight. 'The bus was burned beyond recognition,' a witness said. 'There weren't any seats left. All the windows shattered in the explosion.' Even after escaping the blaze, some passengers had to roll on the ground to extinguish their clothes. One passenger who escaped with burned hair, a blackened face and an injured arm wandered nearby in a state of shock, muttering 'scared to death' over and over. The bus route passes through a busy commercial and residential district, so several people saw the fire. Another witness said: 'The smoke was very high, 40 or 50 metres.' People watching from nearby were afraid to approach. 'We were all scared. We didn't dare look,' said a woman who fled to the back of her restaurant, which was just metres from the scene.