That gas builds up in sewers. They should have tested the air in the hole. Gas mask won’t work. The gas displaces O2. Forced air or ventilation are the only way to enter safely. They were not trained properly or didn’t think and wanted to save a co-worker, this happens more often than people think. We used retrieval harness rope and a tripod to get our people back but we tested the hole first. RIP it’s a shame.
Many “rescuers” , thinking they must react immediately to investigate and retrieve a fallen or unconscious worker, are killed themselves.
/Confined space dangers
Washington state law requires fresh air pumped into the MH, continuous oxygen monitoring, and personnel retrieval system to enter the structure. As a contractor, the cost for these systems are a helluva a lot cheaper than the fine and settlements that follow an incident like this. I don’t call it an accident because it is completely avoidable.
As a young pipefitter I had a superintendent screaming at me to enter a 30 foot deep pit to make a weld. He didn’t care that the safetyman hadn’t checked the pit per the confined space job permit. He was still yelling at me when safetyman showed up and lowered his oxygen monitor into the pit. It alarmed at 10 feet and was full of argon gas. The asshole just stuck is hands in his pockets and walked away.
Like what you said. In thr oilfield, if someone goes down to an H2S release, you leave him. Only when someone qualified and equipped in (thanks to fidelis) SCBA use is sent in can anything be done.