WASHINGTON – The captain of a U.S. Navy aircraft carrier facing a growing outbreak of the coronavirus is asking for permission to isolate the bulk of his roughly 5,000 crew members on shore, which would take the warship out of duty in an effort to save lives.

The ship is docked in Guam. In a memo to Navy leaders, the captain of the USS Theodore Roosevelt said the spread of the disease is ongoing and accelerating, and said that removing all but 10% of the crew is a “necessary risk” in order to stop the spread of the virus.

U.S. Navy leaders on Tuesday were scrambling to determine how to best respond to the extraordinary request as dozens of crew members tested positive.

“We are not at war. Sailors do not need to die. If we do not act now, we are failing to properly take care of our most trusted asset our sailors,” said its Navy Capt. Brett Crozier, in a memo obtained by The Associated Press.

A U.S. Navy official said Crozier alerted commanders on Sunday evening of the continuing challenges in isolating the virus. The official, who spoke on condition of anonymity to discuss internal deliberations, said Crozier wants more isolated housing for the crew and that Navy leadership is reviewing options to ensure the health and safety of the crew.

In Asia, a carrier presence is central to what the Pentagon has identified as a fundamental shift from fighting insurgent and extremist conflicts in the Middle East to a return to “great power competition.” That means, principally, a bigger focus on China, including its militarization of disputed areas of the South China Sea.

The carrier, like other Navy ships, is vulnerable to infectious disease spread given its close quarters. The massive ship is more than 1,000 feet long; sailors are spread out across a labyrinth of decks linked by steep ladder-like stairs and narrow corridors. Enlisted sailors and officers have separate living quarters, but they routinely grab their food from crowded buffet lines and eat at tables joined end-to-end.