The truck laden with iron scrap, on its way to Balasore from Rairangpur, rolled and fell down from a height of about 53 feet near Dwarsali ghat at Bangiriposi on Kolkata-Mumbai NH 6, about 45 km from here this morning, police said.
The truck was completely damaged and disintegrated after it fell.
The driver had apparently lost control over the vehicle while negotiating a sharp bend, the police said.
While six persons, including the truck driver died on the spot, the four injured were admitted to the district headquarters hospital here in a critical condition, the police said.