Six of a family, including two children, died in a collision between two cars and a truck, here on 29 December.
The accident took place early morning when the car drivers could not see a stationary truck on Lucknow-Agra expressway due to heavy fog and collided with it.
According to sources, the crash was so severe that the Santro car, which hit the truck first, got damaged completely and three of the family that was returning from Vaishno Devi temple died on the spot.
The other three died at a hospital. Two people from the other car were said to be seriously injured and being treated.
Passengers in the other car were coming back to Lucknow from Delhi.
The police have taken the truck driver into custody.