Two young brothers who survived an horrific car crash that killed their aunt and critically injured their father and grandmother are believed to have escaped with their lives thanks to their size. Chan Tin-yeung, seven, and Tin-long, five, who were in a serious but stable condition in Princess Margaret Hospital yesterday, had been sitting next to their aunt in the rear seats when their broken-down car was rammed from behind by a truck in Tuen Mun on Sunday morning. The back of the car was completely crushed and the aunt, 41-year-old mainlander Luo Lihong, was killed, but the impact is believed to have thrown the boys into the footwell. 'The boys are small,' a police officer said. 'We believe they were thrown into the space in front of their seats by the impact and escaped life-threatening injuries.' The accident happened less than a minute after their car came to a halt in the middle lane of the three-lane Yuen Long Highway. Luo was declared dead in hospital. The boys' father, Raymond Chan Kwong-wing, 40, was in a serious condition at Tuen Mun Hospital last night, while his mother-in-law, Chan Yuen-wah, 72, was in critical condition. The elder boy's pelvis was injured and his brother suffered head and facial injuries. Yesterday, forensic scientists were inspecting the wreckage at a government vehicle plant on Lantau. The New Territories North traffic unit is also investigating whether the car's hazard lights were switched on. Anyone with information relating to the accident should contact police on 3661 3800. In the first seven months of this year, 64 people died in 64 traffic accidents. There were 117 people killed in 114 accidents last year.