“All of the sudden, there was water in the street,” said Samantha Betti, who was working at a nearby home when she looked out the window to see brown water everywhere. It all happened in an instant, without warning, she said.

Passersby described a sudden, powerful surge of water that filled a long, narrow trench on Dartmouth Street in mere seconds. Workers cried out, “There’s two guys in the hole!” but the water came on too fast. The trench was between 12 to 15 feet deep.

Two construction workers were killed Friday afternoon when a water line burst under a South End street, flooding the trench where they were working with a torrent of water that thwarted desperate attempts to save them.


“It went from nothing to a flood,” she said.

By the time firefighters arrived, just moments later, the whole street was flooded. Firefighters labored into the evening to dig the men’s bodies out, working methodically in tight quarters on their hands and knees, as local and federal investigators tried to piece together what went wrong.

“It looks like somehow a pipe must have broke, and unfortunately they weren’t able to get themselves out of the hole,” said Boston Police Commissioner William B. Evans. “There’s no foul play. It looks like an accident.”

Emergency personnel removed the bodies of the two men by Friday night.

It was unclear Friday how the water line ruptured, authorities said.

The company on the private construction project was Atlantic Drain Service Co., according to three people with knowledge of the investigation, and the company’s trucks were at the scene. The company has a lengthy history of serious safety violations dating back to 2012, and has faced tens of thousands of dollars in fines from the Occupational Safety and Health Administration, federal records show.


A woman who answered the phone at the company’s office declined to comment.

In the Roslindale complex where Atlantic Drain is headquartered, employees were devastated by the deaths of the two men, whom they described as good people.

“There was not one dry eye here,” said a man who asked to be identified only as Greg, who owns a nearby liquor store. One of the men, who was from the South, had a huge family and had just adopted two of his grandchildren, he said.

“I’m going to miss him badly,” he said. “I just saw him yesterday.”

The second victim was from Rhode Island, Greg said.

The Dartmouth Street trench was about 20 feet long and about 2 feet wide, with a wider area near the sidewalk, officials said. The rupture occurred just before 1 p.m.

At least two people working in the trench managed to escape, said two officials with knowledge of the incident.

Workers shouted that there were still two men trapped, and stricken bystanders looked on in horror as police cars, ambulances, and firetrucks roared to the scene.

“A construction worker, his arms flailing, was frantically directing a backhoe operator to lift the metal lid that, presumably, was a manhole,” James Reed, a former Globe staff writer who was in the area at the time, wrote in an e-mail. “Emergency workers were stony-faced as they sprinted through the rising water.”

Jonathan LaPierre was in the shower when the water pressure suddenly dropped. Puzzled, he went to his porch to see what was going on, and heard someone shouting, “There’s two guys in the hole, there’s two guys in the hole,” he said.


“The police came and pump trucks came, and they started pumping out the water as fast as they could,” he said.

Boston Fire Department spokesman Steve MacDonald said firefighters arrived within moments, but the street was too flooded to go into the trench. They had to wait for Boston Water and Sewer Commission workers to shut off the water, he said.

With the water still pouring in, the walls of the trench began to give way, covering the trapped workers in debris. Once the water was shut off, MacDonald said, a large vacuum truck began to empty the trench.

By then, the rescue attempt had become a recovery mission.

The flooding had left gas and electric lines exposed, MacDonald said. Even after it was dried out, the trench was too unstable for firefighters to enter until a “trench box” — a set of walls lowered into the trench in case of further collapse — could be assembled.

Once the trench box was in place, firefighters worked on their hands and knees, gently pulling the dirt away from the bodies of the men in the trench, he said.

Officials said that Atlantic Drain was not working for the city but had been hired by a resident to conduct underground work on Dartmouth Street. Neighbors said work trucks have been parked in the area for most of the week.


A law enforcement official said the company was running pipes from a house to the street.

City officials would not provide information about permits taken out for the work, citing the investigation.

Boston police and the Suffolk district attorney’s office are conducting the investigation of the deaths. OSHA is conducting an occupational hazard review.

Mayor Martin J. Walsh joined investigators at the scene and said the street would likely be shut down for days.

In a statement, officials with the city’s water and sewer commission extended their condolences to the families of the workers.

“We at the commission know first-hand how hazardous utility construction work can be, and today we honor the memory of those who died doing their job to build a better Boston,” they said.

More than 800 construction workers die on the job every year, according to OSHA. Trenching is one of the riskiest types of construction, according to the agency: A cave-in can happen in seconds. About 40 trench workers are killed every year.

Kay Lazar, Meghan E. Irons, and John R. Ellement of the Globe staff and Globe correspondent Olivia Quintana contributed to this report. Evan Allen can be reached at evan.allen@globe.com. Follow her on Twitter @evanmallen.