Gurugram, June 10 -- Two contractual employees engaged to clean a Municipal Corporation of Faridabad (MCF) sewage treatment plant (STP) in Jeevan Nagar Part I died on Tuesday when they lost consciousness after inhaling toxic gases and drowned, police said. The contractor operating and maintaining the plant has been booked for causing death by negligence after police found multiple alleged safety lapses. The workers, both 26 and residents of Moradabad in Uttar Pradesh, lived in accommodation inside the plant in Jeevan Nagar Part I provided by the contractor. Police said one of them had been working at the facility for three years, while the other joined around 18 months ago. According to investigators, the incident took place between 6am and 6.30am when the duo entered the sludge tank after being instructed by the contractor to clean it. A senior police officer said one worker was the first to descend. "He fixed chains with pulleys and secured himself with the safety belts and started to descend at a controlled speed," the officer said, adding that none of the workers had safety equipment such as masks or oxygen cylinders. "It seems he had fallen unconscious while hanging from poisonous gases, due to which his descent speed became fast. At the same time, his safety harness also snapped, and he fell into the tank from several feet high and drowned," the officer added. Investigators said the second worker then attempted to descend manually using holders fixed to the wall but also lost consciousness due to the gases and fell after losing his grip. Police said the brother of one of the deceased workers raised the alarm. Police and the fire department were alerted by 7am. Rescue teams pulled both workers out and rushed them to hospital, where doctors declared them dead on arrival. Investigators said 30 to 40 minutes had elapsed before the duo could be retrieved. Police said family members alleged that workers were repeatedly forced by the contractor to enter the tank without safety equipment. Yashpal Yadav, public relations officer of Faridabad police, said preliminary inquiry revealed that equipment meant to filter garbage from the tank without requiring workers to enter it had remained defunct for several weeks. "Looking at the scenario, we have registered an FIR against the contractor under section 106(1) (causing death by negligence) of Bharatiya Nyaya Sanhita at Mujesar Police Station. He was on the run," he added. Police officials said the incident does not amount to prohibited manual scavenging, and no provisions of laws related to manual scavenging have been invoked. Meanwhile, a senior MCF official said an inquiry has been initiated. "If the contractor is found negligent, then his services will be terminated," the official said. The bodies were shifted to the government mortuary....