AN emergency team was formed within minutes of yesterday morning's train separation, according to an MTRC spokesman. Emergency units were made a feature of accident response after an overhaul of procedures in 1991. The review followed the most serious service breakdown on March 11, 1991, when 500,000 passengers were left stranded for more than six hours after a broken insulator damaged overhead power supplies. A British Rail expert was called in and his recommendations for emergency units to be formed and regular drills to be conducted were tabled before the Transport Advisory Committee. Yesterday's unit, made up of top executives and engineers, was formed to pass on information and co-ordinate a response to the incident, according to the MTRC. Since services began on October 1, 1979, coupler faults have been responsible for at least one other incident among the 10 or so reports of technical faults that had caused MTR train delays. In February 1981, a coupler between two carriages became loose. Checks on all train fleet couplers were carried out. Electrical faults and signal failures were blamed for most of the service faults on the MTR. Several people had been pushed on to MTR tracks by surging crowds at stations, but most escaped serious injury. Train sliding doors that had unexpectedly slammed shut left several commuters with their head wedged between the metal doors, while one man's nose was caught. Station escalators have also injured several young travellers. At least three men died while constructing the MTR. The MTRC has been order to pay out over $3.5 million in compensation to people injured while working on MTR sites.