3 Dead:Warning -- Confined Space+ Sewage/Rotting Material = Death

This happened in a cruise ship in Los Angeles yesterday, but the same hazard may be facing rescue and cleanup workers cleaning up in the wake of Hurricane Katrina as they repair sewer lines, go down into basements or even small enclosed rooms where organic material has been rotting:

Gas Kills 3 Crewmen on Ship

By Hector Becerra and David Pierson, Times Staff Writers

Three crew members were killed and 20 others injured after sewage gushed from a pipe being repaired inside a crowded Royal Caribbean cruise ship docked at the Port of Los Angeles, releasing deadly levels of hydrogen sulfide gas.

Crew members aboard the Monarch of the Seas were trying to fix the pipe in a roughly 10- by 12-foot portion of a propeller shaft tunnel on the starboard side of the ship about 9 a.m. when the accident occurred, officials said.

The workers thought the pipe would be empty, but when they opened it, gas-laden sludge burst out of a 5-gallon sewage container, firefighters said.

Their deaths were "almost instantaneous," said Barbara Yu of the Los Angeles County Fire Department. "Hydrogen sulfide is a deadly gas, and it's heavier than air."

The amount of gas the crewmen inhaled was believed to have been four times the lethal level, Yu added.

Hydrogen sulfide is a sewage byproduct generated by decaying organic material. Also known as sewer gas, it smells like rotten eggs.

At low levels, it can irritate the eyes and throat, but at high concentrations, even a few breaths can cause sudden death.

Officials do not know what triggered the malfunction. The three workers were not wearing protective gear or breathing equipment during the repair effort.

More resources on confined space hazards can be found here.