NEWPORT NEWS, Va. (WAVY) — Three sailors who served on the USS George Washington aircraft carrier have been found dead in less than a week, the U.S. Navy said.

The nuclear-powered Nimitz-class aircraft carrier is currently undergoing refueling and a complex overhaul at Newport News Shipbuilding.

Lt. Commander Rob Myers with the Navy confirmed the deaths Tuesday, but the Navy hasn’t released the cause of death or circumstances surrounding any of the deaths.

The deaths are not believed to be connected and are under investigation separately. The Naval Criminal Investigative Service and local authorities are investigating.

Two of the sailors were found on April 9 and 10 at off-base locations in Hampton, Virginia, Myers said. Retail Services Specialist 3rd Class Mikail Sharp was found on April 9 and Interior Communications Electrician 3rd Class Natasha Huffman was found on April 10.

The third sailor, who hasn’t been identified, was found unresponsive Friday on the carrier.

“The Sailor was treated by the medical team on board before being transported to Riverside Regional Medical Center in Newport News where the service member passed away,” Naval Air Force Atlantic spokesman Michael Maus said in an email to the Navy Times. “The incident is under investigation and the command continues to cooperate with (the Naval Criminal Investigative Service).”

The name of the unidentified sailor will be released when the next of kin has been notified, Myers said.