Sanitation worker Rishi Pal, 50, became the tenth person to die cleaning the city's drains in the past 35 days after he, along with three coworkers, entered a toxic gasfilled PWD sewer line in central Delhi's Lok Nayak hospital on Sunday afternoon without any safety equipment. In a grim repeat of three such incidents since July 16 claiming nine lives, the labourers followed each other into the clogged, 15-foot-deep line after the previous person had stopped responding. Witnesses said Pal was the first to go inside the tank and was knocked unconscious within a few seconds. Two others are battling for life after being rescued in the nick of time.