Washington — A U.S. Navy sailor assigned to the USS Theodore Roosevelt died Monday of complications from COVID-19, the disease caused by the novel coronavirus, the Navy announced. The sailor, whose name is being withheld until next-of-kin can be notified, tested positive for COVID-19 on March 30 and was placed into isolation on Naval Base Guam with four other sailors assigned to the Roosevelt, the Navy said.

The sailor was found unresponsive April 9 during a medical check and admitted to an intensive care unit. The death is the first among Roosevelt crew members.

Four more sailors on Roosevelt have been hospitalized. They are all said to be in stable condition.

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Defense Secretary Mark Esper said the Pentagon is committed to protecting personnel and their families while working to help combat the coronavirus outbreak.

"The entire department is deeply saddened by the loss of our first active duty member to COVID-19," he said in a statement. "Our thoughts are with the family of the USS Theodore Roosevelt sailor who lost his battle with the virus today. "

The Roosevelt, a nuclear-powered aircraft carrier, has been docked in Guam since late March as an outbreak of the coronavirus spread among sailors on the ship. As of Sunday, 585 crew members had tested positive for COVID-19, according to the Navy.

The Navy's handling of the outbreak has come under scrutiny after Captain Brett Crozier, who commanded the Roosevelt, sent an urgent memo pleading for help. Crozier suggested the more than 4,000 crew members should be removed from the ship and placed in 14-day quarantines.

"We are not at war. Sailors do not need to die," Crozier wrote. "If we do not act now, we are failing to take care of our most trusted asset — our Sailors."

Crozier was then relieved of his command after the memo, which was sent to more than 20 people outside the chain of command, ended up in The San Francisco Chronicle.

His firing also led to the resignation of the acting secretary of the Navy, Thomas Modly, who addressed sailors aboard the Roosevelt to explain why he decided to remove Crozier from command of the ship. A recording of his remarks, which included disparaging comments about Crozier, became public, and he tendered his resignation last week.

Esper selected James McPherson, the acting undersecretary of the Army, to replace Modly.

The Navy is conducting an investigation into the episode, and Esper told "CBS This Morning" on Friday that all options for Crozier's future, including reinstatement, remain on the table.

David Martin contributed to this report.