The construction accident occurred underneath a newly paved street in Key Largo at around 8:30 a.m. local time. The workers were investigating why a dip had formed in the new road. One worker entered the manhole when he was overcome by gas fumes.
The two other workers entered the manhole to help the trapped worker, but they also succumbed to the deadly fumes. A firefighter and two Sheriff’s deputies attempted to help the workers, but were met with the same noxious gases that had trapped the three workers. The Miami Herald reports that another firefighter was able to remove his fellow colleague from the hole. Sheriff’s deputies performed CPR on the injured firefighter until paramedics arrived.
Two workers were removed from the hole and pronounced dead at the scene, according to the Miami Herald. The third worker remained trapped in the manhole and is presumed to be dead. The firefighter was airlifted in serious condition to Ryder Trauma Center. The two deputies were taken to Mariners Hospital in Tavernier, and their illnesses are believed to be non-life-threatening.
The gas is believed to be a mixture of hydrogen sulfide and methane, according to the Miami Herald. Officials say drainage holes usually have vents to avoid gas build-ups but that this particular manhole did not appear to have venting. Police and the Occupational Safety and Health Administration (OSHA) will be conducting an investigation.
The following information regarding workplace accidents is provided by the Bureau of Labor Statistics (BLS):