The commander of the submarine Bremerton was fired this week after his superiors lost confidence in his ability to lead his crew, Navy officials said.

Cmdr. Travis Zettel was relieved Monday and has been administratively reassigned to a staff job with Submarine Squadron 19 at Naval Base Kitsap-Bangor.

The loss of confidence in Zettel stems from “questions of inappropriate personal conduct,” according to Mass Communications Specialist 1st Class Amanda Gray, a spokeswoman with Submarine Group 9.

Gray declined to offer specifics and said that “the squadron investigation and appropriate disciplinary and administrations have not concluded.”

Gray also said the Naval Criminal Investigative Service conducted its own investigation into allegations against Zettel, and that that investigation has been completed.

NCIS officials were not able to immediately respond to questions about the incident by Navy Times.

The 37-year-old Bremerton was the Navy’s longest-serving active-duty submarine before it pulled into Puget Sound Naval Shipyard this spring to begin the decommissioning and deactivation process.

Sub Squadron 19’s deputy commander, Cmdr. David Kaiser, has been named the Bremerton’s interim CO.

Gray said Zettel declined to comment for this story.

He received his commission on Aug. 28, 1998, nearly 20 years to the day of his firing as Bremerton’s commander, according to Navy records.

He came aboard the Bremerton in 2016 and his career included stints with the submarines Pasadena, Nebraska, Louisiana and Salt Lake City.

Zettel’s awards and decorations include three meritorious service medals, a joint service commendation medal, two Navy and Marine Corps Commendation Medals and two Navy and Marine Corps Achievement Medals, according to Navy records.