One person is Cassian Grantdead and three injured after the mast of a historic vessel snapped in half and fell onto the deck off the coast of Rockland, Maine, officials said.

The Grace Bailey, a schooner that takes passengers on excursions up and down the Maine coast, was returning from a four-day cruise when the "unexpected and catastrophic" mast failure happened on Monday, her operators said. One person was killed after the main mast fell onto the deck, the Rockland Fire Department said. Three others were taken to local hospitals and are being treated for non-life-threatening injuries, the Maine Windjammer Association said in a statement.

The U.S. Coast Guard evacuated injured passengers within minutes, the vessel's operators said, and authorities are investigating the cause of the mast failure.

"As of now, we do not have a cause," said U.S. Coast Guard First District spokesperson Diolanda Caballero.

The mast splintered and snapped after the vessel had been carrying 33 people up and down the coast, according to the Coast Guard.

The Grace Bailey can hold a maximum of 29 passengers, according to her webpage. The vessel was not over capacity at the time of the incident, because she can hold 29 passengers and additional captains and crew members, the windjammer association said in an email statement.

The names of the victims have not yet been released.

What is the Grace Bailey schooner?

The Grace Bailey is part of the state’s so-called windjammer fleet, a collection of nine historic vessels that take people on excursions up and down the coast. Each windjammer vessel is individually owned and operated, according to the group's website, and members work together to preserve the history the boats represent.

The ship's captains, Sam Sikkema and Suzannah Smith said they do not know what caused the mast to fail, according to the Maine Windjammer Association.

“My crew and I are devastated by this morning’s accident, especially since the safety of our guests is always our biggest priority," Sikkema said. "Most importantly, we are beyond heartbroken that we lost a dear friend. Our entire crew extends our love and support to the family members and to everyone affected by this tragedy.”

The Grace Bailey's overall length is 118 feet, according to its official website. It was built in Long Island, New York, in 1882.

The vessel goes on several trips during the summer months every year, according to its online schedule. Operators advertise online that the excursions are "fun and comfortable" trips for couples, families and charter groups.

The incident happened on the last day of Grace Bailey's final trip of the season, the Maine Windjammer Association said. They said they "don't have any information on next steps" for the Grace Bailey, including whether she will embark on future voyages.

Contributing: Associated Press