The captain of a nuclear aircraft carrier is requesting aid from the U.S. Navy to contain an outbreak of the coronavirus on board his ship.

Capt. Brett Crozier has docked his aircraft carrier, the U.S.S. Theodore Roosevelt, in Guam after cases of the virus that originated in China last year began appearing on his ship. Among a crew of roughly 4,000, more than 100 sailors have tested positive for the pathogen.