The son of killed pipefitter Ray Dobratz told The Associated Press on Tuesday that his father had told him he was working 12 hours a day, seven days a week, for six months.
Erik Dobratz says his father told him others were also working long hours because they were under pressure to finish and were exhausted.
Paul Gaskins, who was working on a steam turbine at the time of the explosion, says they worked 12 to 13 hours every day. He says they were not rushed.
A spokesman for the contractor, O&G Industries Inc., would not comment. A message left at Keystone Construction, where Dobratz worked, was not immediately returned.
On Monday, officials confirmed that assigned to work at the plant the day of the blast had been accounted for and the death toll should stand at five. Limited search efforts were continuing as a precaution.
Mayor Sebastian Guiliano sounded a note of caution Monday afternoon, however, saying rescue crews had been unable to get to all areas of the plant and he could not say for certain that no more victims would be found.
The, about 20 miles south of Hartford, injured more than two dozen in addition to the five dead. It happened as workers were clearing gas lines of air, but the exact cause remained under investigation. Witnesses described the blast as a "sonic boom" that could be felt for 10 miles around.
Investigators from the town fire marshal's office returned to the scene Monday to try to begin determining the cause. Investigators from Occupational Safety and Health Administration were also at the site, which was closed to reporters.
"I lost a couple of good friends up there," Michael Rosario, a representative of the local Plumbers and Pipefitters union, said as he broke down crying Monday.
"We hug our families, kiss our children. ... We go to work and we want to come home at the end of the day, safe," he said. "That didn't happen for a few people yesterday."
The blast left huge pieces of metal that once encased the plant peeling off its sides. A large swath of the structure was blackened and surrounded by debris, but the building, its roof and its two smokestacks were still standing at the site, which is near Wesleyan University on a wooded and hilly 137-acre parcel of land overlooking the Connecticut River.
A team sent by the U.S. Chemical Safety Board, a federal agency that investigates industrial chemical accidents, arrived at the site Monday but was turned away by local police, said Daniel Horowitz, the agency's spokesman.
Melissa Brady, a spokeswoman for Middlesex Hospital, said it treated 26 patients, 21 of whom were released Sunday. Three were admitted to Middlesex and two with severe injuries were transferred, one to Yale-New Haven Hospital and one to Hartford Hospital. She said most had injuries characteristic of being thrown or in an explosion, such as broken bones and bruises.
They were all expected to survive, she said, and most of the injuries were to extremities.
Kleen Energy Systems LLC began construction on the plant in February 2008. It had signed a deal with Connecticut Light and Power for the electricity produced by the plant, and would be one of the biggest built in New England in the last few years.
The company is run by former City Councilman William Corvo. Messages left at Corvo's home were not returned. Calls to Gordon Holk, general manager of Power Plant Management Services, which has a contract to manage the plant, also weren't returned.