FRANKLIN – An Ellsworth man is being called a hero for saving the life of a 16-year-old boy Monday while sacrificing his own.

William O’Coin, 43, died Monday afternoon from asphyxiation in an accident at the University of Maine Center for Cooperative Aquaculture Research, according to state police. O’Coin and the boy were cleaning out a 16-foot-tall concrete tank when hydrogen sulfide gas generated from sludge in the tank overwhelmed them, Sgt. Kelly Barbee of the Maine State Police said. Barbee declined to identify the boy because he is a juvenile.

Steve Eddy, a staff biologist at the facility, said the boy climbed into the tank to simply break up the sludge by spraying it with water from a hose. O’Coin saw the boy succumb to the fumes and yelled for help before climbing down into the tank to save the boy, Eddy said.

“He didn’t think twice about it,” Eddy said of O’Coin. “He just went right down there after him.”

The fumes overpowered O’Coin as well, and the boy’s head went underwater in the tank, according to Eddy. He said he climbed up the ladder propped up next to the tank and yelled to O’Coin who, before he was asphyxiated by the vapors, managed to pull the boy’s head back out of the water.

“Bill’s a hero,” Eddy said. “He gave his life and saved that boy.” Eddy said he nearly climbed down into the tank as well, but instead climbed down to safety because he heard the sirens of emergency vehicles arriving at the scene.

According to Barbee, the boy was taken to Maine Coast Memorial Hospital in Ellsworth in stable condition.

O’Coin’s name was not immediately released to the public as police had trouble locating and contacting O’Coin’s next of kin, Barbee said. Police were able to contact O’Coin’s fiancee in Ellsworth and eventually his mother, who lives out of state, he said.

The tank is in a dimly lit room roughly 50 feet long and 40 feet wide, according to university officials at the scene. Jake Ward, university director of industrial cooperation, said the 20 smaller green tanks in the room, which are fed recycled water from the tank O’Coin was cleaning, are used for cultivating halibut, which normally live in low-light conditions.

Eddy said that cleaning the 6-foot-wide tank, which is sunk four feet into the floor, was not a routine task. In the two years he has worked at the facility, Eddy said, that tank has never been cleaned.

“It seemed like a routine thing,” Eddy said. “We had no idea it was toxic down there.”

Barbee said the Maine Department of Labor will investigate the accident because it occurred on state property. O’Coin and the boy were not using safety equipment at the time of the accident, he said. What, if any, equipment they should have been using will be determined by investigators, he said.

University spokesman Joseph Carr said O’Coin had worked at the facility for six years, the past three as the systems manager for the university and the previous three for the facility’s previous owner, Integrated Food Technologies.

Eddy said O’Coin was well-liked at the facility and tended to leave a favorable impression on other people.

“I’ve had people describe him as the nicest man they ever met,” Eddy said. “He was a really good guy.”