The Navy brass was warned: the Covid-19 coronavirus was spreading fast in the close quarters of the USS Theodore Roosevelt. Sailors could die.

And now one has.

The Navy announced Monday that a sailor from the Roosevelt who was being treated at a Navy intensive care unit in Guam has died of “complications” arising from Covid-19 — the first active-duty US service member to succumb to the virus.

The sailor’s identity was not released pending notification of next of kin.

Capt. Brett Crozier, former commander of the Roosevelt, had issued a forceful warning to his superiors, a warning that inevitably leaked to the public.

“We are not at war. Sailors do not need to die,” Crozier wrote in a memo on March 30, less than two weeks ago, pleading for immediate help to protect his crew.

Two days later, Crozier was fired by then-acting Navy Secretary Thomas Modly, who said Crozier violated military protocols.

At that time, about 70 sailors aboard the ship had tested positive for the virus. Now there are nearly 600 among the huge ship’s crew of almost 5,000. Among those testing positive: Crozier himself, who is now in quarantine.

When Crozier left the ship on April 2, a huge crowd of sailors cheered, chanting his name like a star quarterback who had just saved the big game.

Modly appears to have taken that as a personal insult.

Angered, he flew directly to Guam — a flight that cost nearly a quarter of a million taxpayer dollars — to deliver a 15-minute, profanity-laden speech aboard the Roosevelt, reported the New York Times.

Modly told the sailors it was their duty not to complain. He insulted Crozier, calling him “naïve” and “stupid.”

“Everyone’s scared about this thing,” Modly said. “But I’ll tell you something: If this ship was in combat and there were hypersonic missiles coming at it, you’d be pretty fu**ing scared too. But you do your jobs. And that’s what I expect you to do.”

This did not sit well with the crew, or with many in Washington.

“Modly’s comments sparked intense backlash from lawmakers and the ship’s sailors. Modly later walked backed his comments and apologized,” the Times said, adding that Modley resigned last Tuesday.

In his departing message, which was obtained by the Navy Times, Modly blandly called his fiery speech “a poor use of words.”

The sailor who died had tested positive for the virus on March 30, the same day Crozier wrote the memo that triggered the whole tragic sequence of events.

As for the Roosevelt, nearly 4,000 crew members have evacuated the ship in Guam, many of them now quarantined in hotels. Fewer than 1,000 sailors remain aboard the ship.