A young laborer was seated on a looped chain as he was being lowered into a 21-foot (6.4-meter) deep manhole to prepare for utility construction work. He was at the approximately 17-foot (5.18-meter) level for about 20 seconds when he started gasping for air. He fell from the chain seat and landed face down in water that had accumulated at the bottom of the manhole. An autopsy determined the cause of death was lack of oxygen. A manhole is a confined space, which means the air ventilation is poor. As a result, toxic gases can build up, or the atmosphere can lose […]