Four industrial workers died after inhaling hydrogen sulphide gas that leaked from a chemical factory in Tarapur on Tuesday evening. Seven other workers were taken to hospital, three of whom were unconscious till late at night. The other four were reported to be out of danger. The leak occurred at around 7.15 pm on the premises of SeQuent Scientific Ltd, at a plant that makes veterinary drugs, within the Maharashtra Industrial Development Corporation’s (MIDC’s) industrial zone at Boisar, Tarapur. Police, emergency personnel and officials from the Maharashtra Pollution Control Board rushed to the spot and plugged the leak, said an official from the government’s disaster department. Sanitisation efforts were initiated, which went on till late in the night. “We immediately sent our officers to the spot... We will take action if a case of negligence is established,” Rajesh Mor, SP, Thane (Rural), said. A PTI report identified two of the dead workers as Haresh Yadav and Vishnu Singh.