Two men who were trapped in the sewage plant of Vivanta by Taj Ambassador near Khan Market in Delhi and inhaled toxic gases on Sunday died on Tuesday at a hospital, reported The Indian Express. Three other workers who were also trapped in the sewage plant are still undergoing treatment. The workers were reportedly not wearing safety gear when they entered the plant.

A five-member team was sent to fix a leak that was reported at the sewage treatment plant, located in the adjoining building of the hotel. Ravinder Kumar, a contractual maintenance staff at the sewage treatment plant run by Eco Pollutech Engineers, was the first person to enter the plant, reported The Hindu.

Kumar is believed to have collapsed inside the plant, after which four other workers entered the plant to help him. However, they also collapsed. The men were frothing at the mouth when rescuers found them, reported The Indian Express.

Kumar and Vikram, a 26-year-old who worked as a security guard at the hotel, died at Moolchand Hospital on Tuesday, said Madhur Verma, deputy commissioner of police (New Delhi), according to PTI.

The medicolegal case report of the deceased showed that particles of hydrocarbons were found in the lungs. The autopsy reports are likely to be ready this week.

A case was filed under relevant sections of the Indian Penal Code against Eco Pollutech Engineers and the hotel, including for culpable homicide. “We are providing all possible support to their families,” a spokesperson of Vivanta by Taj said, according to The Hindu. “Vivanta Ambassador is fully cooperating with authorities in the investigation of this incident.”