Nine people lost their lives after inhaling a chemical while they were cleaning a storage tank at an oil processing facility in Latur on Monday night, state police said on Tuesday. According to police, some of the workers had entered the tank owned by Kirti Oil Mills to clean it. When they did not come out their colleagues who went to check on them also inhaled the chemical and fell unconscious, police said. The authorities who were informed late Monday night pulled out the employees, seven of who were declared dead at the hospital. Two of the three employees undergoing treatment passed away on Tuesday while the condition of the third remains critical. Maharashtra Labour Minister Sambhaji Patil Nilangekar, who visited the site, told reporters that the mill had been sealed for the purpose of investigation. Four people, including the owner of the mill, Kirti Bhutada, had been arrested, police said. The dead have been identified as Dagdu Pawar, Baliram Pawar, Narendra Tekale, RD Shinde, Maroti Gaikwad, Rambhau Yerme, Akash Bhute, Parmeshwar Birajdar and Atkare Shivaji.