At a Queens, New York waste transfer station, investigators read the signs of a tragic story: Harel Dahan, 23, descended a ladder into a stinking well that caught runoff water from the recycling yard, and was overcome by hydrogen sulfide fumes. His father, Shlomo Dahan, 49, went down after him but was also overcome by the fumes. Rene Francisco Rivas, 52, tried to help the two men but met the same fate. A firefighter wearing protective clothing and enclosed breathing apparatus retrieved the three workers’ bodies from the well.

Shlomo Dahan’s company, S. Dahan Piping and Heating Corporation, had been contracted by the Regal Recycling Company to vacuum out the well, and Rivas was a Regal employee. The New York Times’ Robert D. McFadden notes that OSHA fined the plant $1,500 in 2006 after a worker was crushed to death by a wheel loader, and identified several serious violations at the facility in an inspection conducted earlier this year.

In a follow-up Times article, Ray Rivera points out that this kind of scenario – where one worker is overcome by fumes, and other workers die trying to save their colleague – is all too common, especially in the waste management and sewage industries:

“I think it’s a natural reaction to run in there and see if a person is O.K.,” said Dr. Robert G. Hendrickson, an Oregon physician who has studied co-worker fatalities in hydrogen sulfide deaths. “And I think there is this secondary thought process in workers to think: ‘That person was down there for a while and that’s why they passed out, and if I run down real quick, I’ll be O.K.’ ”

Last year, two employees of a Schenectady waste cleanup company died after one climbed into a waste tank to make repairs and was quickly overcome by fumes, followed by the second worker, who tried to pull him out. In 2007, four workers died at a Wisconsin landfill pit after one was overcome by fumes and the next three, one after the other, made fatal rescue attempts.

Dr. Hendrickson and two co-researchers found that in 42 incidences of workers’ dying of hydrogen sulfide toxicity between 1993 and 1997, more than one-fifth involved multiple deaths, including co-workers killed while trying to rescue a colleague. In all, 52 workers died over that period. The deaths have mounted despite strict standards governing work in confined spaces set by the federal Occupational Safety and Health Administration.

There are standard precautions for entering such a confined space:

“What they should have done before anyone went into this hole, they should have sampled the air for hydrogen sulfide,” said Gary M. Hutter, a safety consultant who teaches OSHA compliance at the Illinois Institute of Technology.

The first person to descend should also have been in a harness system attached to a hoist, Mr. Hutter said, “so if he passes out they could have had a mechanism to pull him back up without anyone going in.”

The crew should also have had self-contained breathing equipment nearby and written procedures, known by OSHA as an “entry permit,” detailing a rescue plan, among other requirements, Mr. Hutter said.

OSHA is investigating what happened at the plant, and whether S. Dahan and Regal followed all of the relevant regulations.

It’s important for people to realize how often confined-space rescue attempts by workers without the right gear turn into multiple fatalities – but it’s also hard to fault someone for racing to rescue a co-worker despite the dangers. After hearing from firefighters that Rene Rivas had died trying to save Harel and Shlomo Dahan, Rivas’ son, Oscar Rivas, said “He was always like that, always helping people. He was a good person.” Our thoughts go out to the families of all three men.