The cause of the Indian train accident was______.

At least 80 people have died in a derailment of a luxurious train in eastern India, which some government officials say could have been caused by terrorist sabotage. An investigation has been ordered to identify the cause of the accident.
    There were nearly 600 passengers and staff on board the train. It was going from the eastern city Calcutta to New Delhi, when it was wrecked late Monday night.
    The train derailed as it was crossing a bridge over the Devi river near Rafiganj station, in the eastern Bihar state. One of the couches sank in the river. At least two others hung precariously from the bridge. Several others left the tracks.
    The accident occurred in a remote area with poor telecommunication links. Many victims remained trapped in the wreckage through the night before they were rescued.
    A spokesman for Eastern Railways says rescue operations were slowed down by bad weather, but are now fully under way.