The Gaisal train disaster occurred on 2 August 1999, when two trains carrying about 2,500 people collided at the remote station of Gaisal in West Bengal. Owing to a signalling error, both trains were using the same track on a day when three of the four tracks on the line were closed for maintenance. Their combined speeds were so great that the trains exploded on impact, killing at least 290 people. Collision The crash occurred at about 1:45a.m. on 2August, 1999, when the Avadh Assam Express from New Delhi collided with the Brahmaputra mail at Gaisal railway station, Uttar Dinajpur, West Bengal, 19 kilometers from Kishanganj. Through a signaling error at Kishanganj, the Avadh Assam Express from Delhi was transferred onto the same track as the mail train. No one on either train or in the signals and station master's office noticed the error. The staff at intermediate stations between Kishanganj and Gaisal also failed to notice that the Assam express was on the wrong track. As a result, Brahmaputra Mail train crashed headlong into the front of the Avadh Assam Express at Gaisal. The Avadh Assam Express WDM-2 locomotive was thrown high in the air, and passengers from both trains were propelled into the neighbouring buildings and fields by the force of the explosion. Failures Three of the four lines at Kishanganj station were non-operational because a doubling of lines was in progress. Only one line was being used to carry the load usually carried by four: 31 trains per day. Track circuiting and interlocking were also not correctly functioning at the station, because of the work in progress. Track circuiting is an electrical procedure by which the station master, and consequently the train driver, can know that the track ahead is occupied. The signals will remain red, interlocking the track, which effectively means that the series of signals cannot be turned green unless the station master allows. The signals can be changed from the relay room which can only be opened jointly by the station master and the signal inspector. In such a situation, the points in the track have to be set manually by a "cranking" procedure, whereby a crank handle, available at stations, is rotated manually on the orders of the station master for setting the points, which are then clamped and locked. The entire process takes around 30 minutes. The driver B.N. Roy who was