The family members of Murugaiyaan (55) were sleeping on the platform adjacent to a railway track used for berthing goods trains when the tractor driver lost control and ploughed through them in the wee hours in the town in Tiruvarur district, they said.
The incident occured 200 feet from the railway station and the tractor was carrying sand for a track being laid from Mannargudi to Pattukottai.
Murugaiyaan and his three children aged between three and ten were killed on the spot. His wife and two other relatives were injured and had been admitted to a hospital, police said.