Police said a sewage suction truck, bound to Tiruchy from Bengaluru, was stationed along the road near Thoppur after it developed some snag.
Police said 12 persons, including truck driver Ranjith Kumar, 30, from Virudhunagar and Rathinavel, 26, from Tiruchy were engaged in repairing the faulty vehicle, when a potato laden truck driven by Siddhaiyan, 42, from Salem district heading to Tirupur from Hosur rammed into it and fell on its side.
Soon, two other trucks, a boulder laden one bound to Palani from Krishnagiri and another container truck hit the potato laden truck one by one. In the impact of multiple collisions, the sewage suction truck was pushed into a pit along the road.
Police said Rathinavel and Siddhaiyan were crushed to death on the spot, while others with injuries were rushed to Dharmapuri Government Medical College and Hospital. The bodies of the two deceased were sent for a post mortem.
Salem range DIG S Maheshwari and Dharmapuri district Superintendent of Police C Kalaichelvan visited the accident spot. Traffic was disrupted on the busy Bengaluru-Salem National Highway for several hours due to the mishap.