1,000-foot container vessel breaks free from Southie terminal

A 1,065-foot vessel drifted away from the Paul J. Conley Container Terminal in South Boston early Wednesday, causing damage to another pier before tugboats caught up to the massive ship, officials said.

The incident unfolded around 12:45 a.m. when the Helsinki Bridge container ship “broke free from its mooring” at the terminal, the US Coast Guard said in a statement.

“Terminal workers who were aboard . . . were able to safely disembark, and no injuries or pollution from the container ship were reported,” the release said. “A docking pilot boarded the vessel, and along with the container ship’s crew, safely escorted the Helsinki Bridge to Broad Sound, where it remains anchored.”

The ship was carrying general cargo, according to the Coast Guard.

“The cause of the incident remains under investigation,” the statement said.

No further information on what caused the mishap was available.

Massport said Wednesday afternoon in a statement that the ship had been docked for about 12 hours before it “moved 300 feet across the Reserve Channel and caused some damage to the end of the 88 Black Falcon pier. . . . The ship is currently anchored in the harbor off of Nahant. Damage assessments to both Conley Terminal and 88 Black Falcon are also being conducted. Massport is working closely with the Coast Guard on the investigation.”

It wasn’t immediately clear when the vessel would return to the Conley terminal, which Massport says is a hot spot for shipping.

“All of the world’s leading container lines ship through the Port of Boston’s Conley Terminal, moving nearly 1.5 million metric tons of cargo each year,” the agency says on its website. “In 2016, Conley Container Terminal saw record-breaking growth with a 5 percent increase in container volume, setting a new record of more than 248,000 TEUs (20-foot equivalent units) shipped through the terminal. This is a testament to the technology, the convenience, and the efficiency of the only full-service container terminal in New England.”

The Helsinki Bridge has stopped at terminals far and wide in recent weeks.

Recent stops include terminals in the Chinese cities of Qingdao, Ningbo, and Shanghai, as well as Busan in South Korea, and Jersey City, according to the website of the Yang Ming Marine Transport Corporation.