Eighteen people, including 14 women, were killed when a train smashed into an van at an unmanned level crossing near Kancheepuram on Tuesday, police said.
The victims from Orikkai village were on their way to the funeral of a woman in Pudupakkam, about 10 kms from Kancheepuram, when the accident occurred.
The daughter and granddaughter of the dead woman were among those killed in the accident, police said.
The van in which the victims were travelling was going through the crossing when it broke down and got stuck on the tracks.
Soon after, the suburban electric train from Tirumalpur to Chennai Beach rammed into the van, killing all its occupants, including the driver, police said.
Kancheepuram's Superintendent of Police A Amalraj said that 18 bodies had been recovered.
The impact was so severe that the auto was pushed and dragged for nearly a kilometre before the train stopped and the bodies were badly mutilated, police said.