THE mother of a 12-year-old boy who was left scarred for life after being badly burned on a school picnic is suing for negligence. Kok Pak-sam's uniform caught fire after a classmate poured alcohol on dying barbecue embers during an outing to Lai Chung Country Park. A writ filed in the Supreme Court yesterday claimed the schoolboys' teacher, Chan Wai-yee, had left a group of six pupils unsupervised. Pak-sam, who was 10 at the time, was standing by the barbecue when Lam Tin-hoi took out a bottle of alcohol and splashed some on the charcoal, the writ says. Because the fire was still weak, Lam drenched the barbecue again. The writ states: 'At that time Kok Pak-sam was standing about two metres away from the stone stove and facing the fire when a blaze suddenly blew towards him. His clothing caught fire and he sustained severe personal injuries.' Pak-sam's mother, Ho Yin-bing, claims the accident on December 12, 1992, was caused by the negligence of the Sha Kok Primary School, Sha Tin, or its teachers. The writ accuses them of not telling pupils of the danger of putting alcohol on a fire or warning Pak-sam not to stand too near the barbecue. Ms Ho also says the teachers omitted to take fire extinguishers on the picnic. Pak-sam, who has been in and out of hospital for 21 months, was left with three facial scars as well as burns to the neck and ears. Ms Ho is suing for at least $25,580 for medical expenses and lost earnings while she cared for her son.