ORONO – A Sullivan teen-ager saved Monday from asphyxiation by a co-worker who died rescuing him is at the intensive care unit of Children’s Hospital in Boston.

The 16-year-old boy, identified as George Schaefer, was in serious condition Tuesday after being moved Monday from Maine Coast Memorial Hospital in Ellsworth, University of Maine officials said Tuesday afternoon at a campus news conference.

William O’Coin, 43, of Ellsworth, Schaefer’s co-worker, was killed after he helped the boy out of a concrete tank the pair was cleaning at the University of Maine Center for Cooperative Aquaculture Research in Franklin. O’Coin suffocated from hydrogen sulfide gas that had built up in sludge at the bottom of the tank.

This is the first accidental work-site death in the university’s history, according to university officials.

The university may have been in violation of federal work safety standards at the facility, according to state labor officials investigating the accident.

O’Coin and Schaefer were cleaning roughly 4 inches of sludge out of the 6-foot-wide concrete tank Monday afternoon when the accident occurred, according to state police. Schaefer was in the tank, spraying water from a hose on the sludge and was overpowered by hydrogen sulfide fumes, which are generated naturally by the sludge or stagnant water, facility employees said.

O’Coin yelled for help, emergency personnel were called and the man then climbed down to assist the boy but was overcome by the vapors himself. Schaefer slumped in the water and O’Coin managed to pull the boy’s head out of the water in the tank before he succumbed to the gas, they said.

Although Schaefer had been exposed to the toxic gas, he was able to climb out of the tank on his own, according to Jake Ward, UM’s director of industrial cooperation and the administrator for the center in Franklin.

The tank, which was used to recycle water used for cultivating halibut, was part of a sealed system and wasn’t designed to be cleaned. The system water had tested positive for hydrogen sulfide about a week ago, Ward said.

As the systems manager and safety coordinator at the facility, O’Coin drained the multi-tank water recycling system, including the 16-foot-high, aboveground, concrete tank.

Ward said neither O’Coin nor Schaefer was using safety equipment at the time of the accident. Ward said after the conference that O’Coin had been trained in hazardous materials, although Schaefer had not.

Schaefer was a summer employee and the only high school student employed at the facility, although a number of college-age students worked there, Ward said.

No one at the facility was aware that the hydrogen sulfide had built up in the sludge, the UM official said. It had gathered in the bottom of the tank because the pipe for pumping water back out of the tank sits about 8 inches above the bottom of the tank.

“I would say it’s a poor design,” Ward said. The UM official said it was thought that the tank hadn’t been cleaned since the facility was built in 1989.

A colorless gas that is heavier than air, hydrogen sulfide smells similar to rotten eggs, although the odor is usually unnoticeable after the second or third breath. The gas can irritate or and even paralyze the lungs.

Schaefer survived the incident and was taken in stable condition to Maine Coast Memorial Hospital in Ellsworth, according to state police. He later was taken to Eastern Maine Medical Center in Bangor before being transferred to Boston.

UM President Peter Hoff said during the press session that the university would leave no stones unturned in learning how the accident could help prevent similar occurrences.

“We refuse to accept the idea that anyone’s life should be in peril on the job,” Hoff said. “Our primary goal is to make sure that we do what we can to avoid having something like this again.”

Hoff said the university has closed the part of the facility where the accident happened. He added that the university would help both families with any services it could provide and provide counseling to any other employees at the Franklin facility.

UM spokesperson Joe Carr said that employees at the Franklin facility had the option of not reporting to work Tuesday and that some did stay at home.

He said university grief counselors will be available to staffers grieving from the accident and will meet this week with those seeking such assistance.

Funeral services for O’Coin will be held Saturday in Ellsworth.

Ward said the university is conducting its own investigation. Preliminary evidence shows, however, that employees at the Franklin facility may not have been following safety regulations, according to state investigators.

Michael Frett, director of the state’s Bureau of Labor Standards, said Tuesday that the bureau’s investigation into the fatal accident shows that some of the practices at the center may have violated federal Occupational Safety and Health Administration rules.

David Wacker of the bureau’s Workplace Safety and Health division went to the facility Monday afternoon to investigate the factors that led to the asphyxiation death of O’Coin, he said.

“He does believe some OSHA violations do exist,” Frett said of Wacker’s investigation.

How long those violations have been in effect and whether they contributed to O’Coin’s death have not yet been determined, Frett said.

The state agency is responsible for enforcing federal OSHA rules on public property in Maine, according to Frett. OSHA itself is not expected to participate in the investigation of O’Coin’s death, he said.

Frett said that the university could be fined if final results of the investigation indicate safety rules were violated. He would not specify what fine or range of possible fines the university could end up paying.

Frett said that Wacker’s preliminary investigation could be complete Tuesday afternoon, but that Wacker’s final report likely will not be completed until Friday.