Traffic in Kowloon's busy downtown was severely affected most of the day yesterday after a freshwater pipe had burst in Tsim Sha Tsui. At about 6.30am, the 25-year-old underground pipe suddenly began gushing water onto Nathan Road between Salisbury and Middle roads - one of West Kowloon's busiest intersections. The Transport Department established a special unit to monitor traffic. The road was closed to vehicles and 25 bus routes were affected. The road reopened at about 4pm. Water supplies to homes, offices and many hotels in the area were not affected, as the broken pipe supplied water only to the Cultural Centre and a department store on Salisbury Road. Tankers were deployed until the water supply returned to normal at 1pm. Sandbags were placed around the Peninsula and Sheraton hotels to prevent flooding as the water level rose by more than 30cm. Acting assistant director of the Water Supplies Department, Wong Kwok-hung, apologised for the incident - the second of its kind in two days. On Monday, the water supply to Heng Fa Chuen was affected after a water main burst. A worker from the water department was still in critical condition at Pamela Youde Nethersole Eastern Hospital last night, after being struck on the head by a 20kg stopcock that was ejected like a cannonball from the burst main. Chan Shu-pui, the department's chief engineer for Kowloon, said the pipe in Tsim Sha Tsui was scheduled to be replaced this July. 'We inspected the pipe regularly but found no problem. But then it broke by accident after all,' he said. 'No one could have expected it.' The water department said the road would be partially closed again last night, as workers needed to make repairs, but it expected the road to be fixed before today's rush hour. The department said that in the past two years, there were on average 111 burst mains per month resulting in suspensions of water supply. Of those cases, 50 involved freshwater mains, with the rest salt water.