Three workers at Salem Harbor Power Station died after they were severely burned by high pressure steam when a water tube on a boiler exploded, authorities said Wednesday.

Dominion, the Richmond, Va.-based energy company that owns the power station, said the men were working on the ground floor near the boiler on Tuesday when the tube ruptured about 20 feet above and blew steam on them. The men suffered severe burns on their heads, hands, faces and necks.

Matthew Indeglia, 20, who has addresses in Lawrence and Townsend; Mark Mansfield, 41, of Peabody; and Phillip Robinson, 56, of Beverly, died after being taken to Brigham and Women's Hospital in Boston, according to Salem police Detective John Doyle.

A hospital spokeswomen said the men died between Tuesday night and early Wednesday morning.

The company said two were operators and one was a mechanic.

"All of Dominion is greatly saddened at the deaths of these men," said Thomas F. Farrell II, Dominion chairman, president and chief executive officer. "They were valuable members of our Salem Harbor family. Our thoughts and prayers are with their families."

The federal Occupational Health and Safety Administration has inspected the plant once in the last five years, in March 2006, and no citations were issued, OSHA spokeswoman Ted Fitzgerald said. The agency is investigating Tuesday's accident, Fitzgerald said.

The power station was shut down Wednesday for an undetermined period so the company could assist employees and conduct a full safety review, the company said.

The boiler tubes contain high-pressure, high-temperature water and steam that turn the turbine-generator, which spins to produce electricity. The company said there were no indications of any problems before the rupture.

The coal-fired plant was purchased by Dominion in 2005. It employs 145 people and produces enough electricity for 740,000 homes.