CHARLESTON, S.C. (WFLA) — The Federal Bureau of Investigation said it is investigating a “suspicious death” of a passenger aboard the Carnival Sunshine.

FBI Columbia said the woman died during the ship’s Feb. 27 voyage to Nassau, Bahamas.

“Medical staff and other crew members of Carnival’s Sunshine were made aware of the passenger being unresponsive and immediately attempted life-saving measures. Despite their efforts, the passenger was pronounced deceased on the ship,” a spokesperson for the Columbia field office said in a statement.

When the ship returned to port in Charleston, South Carolina on March 4, members of the Evidence Response Team (ERT) responded to process the passenger’s room.

According to the FBI, the incident was isolated and there was no threat to any other passengers before or after the passenger was found deceased. The FBI said it investigates certain crimes on the high seas, as well as suspicious deaths of U.S. persons.

Carnival Cruise Line released an update on the woman’s death on Tuesday.

“While we continue to cooperate with authorities, all indications pertaining to the death of a guest on board Carnival Sunshine suggest that it was a natural death due to a medical condition,” a spokesperson for the cruise line said. “We will defer to the FBI on any specific details which may possibly be released at a later date as we fully respect the investigative process, but our initial emergency medical response was appropriate and it appears that this was indeed a medical situation that sadly resulted in the death of a guest.”

The incident remains under investigation.