The mishap took place at Kandalapalam village when the family was going to Rajolu village from Mandepeta to celebrate the new year, Police Inspector C V Ramana of Ravulapalam police station said.
"The driver lost control over the vehicle and it fell into the canal. After reaching the spot, police fished out bodies of four persons", he said, adding they have been shifted to a hospital for post-mortem.
According to the officer, the deceased have been identified as Gandham Gopikrishna(50), his mother Saraswavati (70) and his sisters B Ammagi (40) and M Subbalakshmi(42).