Six double-decker buses, worth more than HK$1 million each, were destroyed and four others slightly damaged in a fire at a Kowloon Motor Bus depot in Tin Shui Wai at about 1am yesterday. Firefighters put out the blaze in Tin Pak Road about 45 minutes later. No one was injured. Police said the blaze was believed to have been caused by a short circuit in one of the buses. A KMB spokeswoman said the 10 vehicles had been in service between 31/2 and 10 years.