Three labourers were killed while two others sustained injuries after an explosion occurred at an industrial unit in Vasai around 7.45am on Tuesday.
The unit, Nakoda Extrusion, is located in the Bhoidapada area of Vasai (East). It is an aluminium profiles manufacturing unit, said the police.
Five labourers were waiting for their supervisor, who usually arrives at 8am, outside the unit, which was closed at the time of the incident, police said.
"For the manufacturing process, they heat a certain gas in huge boilers inside the unit. The material has to be heated to 200 degrees centigrade, hence the boilers are kept running overnight at least three times a week. This was the case on Monday night. Prima facie, it appears the pressure in the boilers increased, leading to the explosion," said Deepak Devraj, deputy superintendent of police, Thane (rural).
Two of the labourers, Sudhir Yadav, 33, and Nirmal, 34, were declared dead on arrival at Platinum hospital, Vasai. Another labourer, Kanhaiya, 30, died during treatment at the hospital. All three bodies were sent for post-mortem. Two other labourers, Praful and Kailash, sustained injuries.
"There was a deafening sound and we were thrown at a distance owing to the explosion's impact," said Kailash.
The police are probing the exact cause of the incident, said Devraj, adding that there was no firefighting equipment fitted inside the unit. "We have registered a case under relevant sections of the IPC against the unit owner, Jeevan Jain and manager, Jeetubhai Chanchad. No arrests have been made so far," Devraj said.