The United States Coast Guard is investigating how a container ship broke free from a South Boston terminal early Wednesday morning.
Authorities said they received a call at 12:45 a.m. after the 1,065-foot container ship, the Helsinki Bridge, had broken all 12 lines when it was moored at the Paul W. Conley Container Terminal.
"It's not common, especially in this port, but it isn't unheard-of, either," said U.S. Coast Guard Lt. Jennifer Sheehy.
Coast Guard officials said 10 Conley Terminal members were on board the vessel when it broke free in addition to the Helsinki's crew.
Longshoreman Stephen Picard was one of the terminal members on board when the ship's lines snapped.
"I saw the lines snap and it was a big thump," he said. "When I looked down to the front of the ship, I noticed the ship started pulling out, so we had to run back up the gangway."
The ship caused some damage to the end of the 88 Black Falcon pier, according to Massport.
Picard said part of it even hit a crane and that the crane operator jumped into action putting his life at risk to save others.
"He was caught between the house of the ship and the containers in the next hatch over," Picard said. "The house was actually, I believe, rubbing up against his crane, so he tried to move the crane down and pull it in to save the crane and the people below him."
Once the Coast Guard, Massachusetts State Police, Boston Police and Massport Fire responded, the Conley employees were removed from the vessel and a pilot boat escorted the Helsinki to Broad Sound — between Nahant and Winthrop.
No injuries or pollution from the vessel were reported.
Coast Guard officials said the incident is under investigation but indicated that strong winds may have played a role. The ship had been docked for 12 hours prior to the incident.
"We have a team that just got on board to Helsinki Bridge out in Broad Sound so they're going to be asking questions of the crew and kind of survey the equipment to see what might've happened. We're not sure yet," Sheehy said.