KARACHI - Three employees of Karachi Water and Sewerage Board (KWSB) were killed due to suffocation of poisonous gases during cleaning work in a sewerage drain in the limits of Baghdadi police station in the wee hours of Friday. SHO Jan Muhammad said the incident occurred near Peshawari Hotel where the staff of KWSB was busy cleaning the sewerage lines with automatic machines. He said during the work, a sanitary worker Babar fell down into the open manhole. Upon his shouting, his three colleagues Razzak, Fayyaz and Waddo jumped into the manhole to rescue him. A large number of rescue workers and police rushed to the spot and tried to save all the four workers. However, after the hours long hectic efforts, the rescue team recovered the bodies of three sanitary workers Razzak, Fayyaz and Waddo while Babar was recovered in unconscious condition and admitted to Civil Hospital Karachi. Officer further said that all the deceased were middle-aged men and residents of Essa Nagri, Hassan Square area. Two of them Razzak and Fayyaz are unmarried. To a question, the sources of KWSB told that due to busiest traffic area, all the sanitary works do their work in night. Police handed over the bodies to their heirs.