Six people were killed and three injured in an explosion on Wednesday at a firecracker unit at Mannargudi, about 28 km from here, a fire and rescue official said
The explosion was triggered when the workers were handling raw materials to make crackers in the unit, he said.
The owner of the unit was among the deceased.
The explosion was so powerful that the building that housed the unit collapsed and portions of it were flattened, he said, adding there was no blaze.
"While four of them were flung outside under the impact of the explosion, two got trapped under the rubble and all of them died," a rescue official told PTI.
Several teams of fire and rescue personnel from here and nearby areas were pressed into service to rescue the victims and clear the rubble.
The two seriously injured workers were admitted to a nearby Government medical college hospital, while the other man was discharged after treatment, he said.