The Gaisal train collision occurred on 2 August 1999, when two trains carrying about 2,500 people collided at the remote station of Gaisal in West Bengal, India. 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 285 people.