The coronavirus outbreak aboard the aircraft carrier USS Theodore Roosevelt started in the reactor department, according to The New York Times.

The USS Theodore Roosevelt has two nuclear reactors on board that provide energy for ship electrical and propulsion systems, systems that require a specialized crew of reactor operators and maintenance technicians.

The first three cases were reported on March 24. Since then, the number of coronavirus cases aboard the carrier has risen to nearly 600.

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The first US Navy sailors to fall ill aboard the coronavirus-stricken aircraft carrier USS Theodore Roosevelt were those running the nuclear reactors, The New York Times reported Sunday evening.

The Navy first announced that three crew members aboard the aircraft carrier had tested positive for the coronavirus on March 24, and that initial outbreak reportedly started in the reactor department.

The Nimitz-class nuclear-powered aircraft carrier USS Theodore Roosevelt has two nuclear reactors on board that serve as the heart of the ship and are responsible for providing power to the ship's critical systems. Specifically, the reactors serve as the primary energy source for electrical and propulsion systems.

While details are limited, an outbreak among the reactor crew could easily be considered a worst-case scenario, as losses in the reactor department could put the ship out of commission because it would fail to have the required number of technicians or operators to safely run both reactors at sea.

In response to the coronavirus outbreak, the USS Theodore Roosevelt pulled into port in Guam.

As the number of coronavirus cases aboard the aircraft carrier climbed in the days that followed the initial outbreak and as warship doctors reportedly warned that more than 50 people could possibly die, Capt. Brett Crozier, then the carrier's commanding officer, wrote a letter pleading with the Navy for additional assistance.

On March 30, Crozier sent out a letter warning that "the spread of the disease is ongoing and accelerating." In his plea, he called on the Navy to take decisive action and evacuate the overwhelming majority of the crew. "Sailors do not need to die," he wrote, adding that if nothing is done, "there will be losses."

The New York Times reported that other senior officers on the carrier wanted to sign their names on the letter, but Crozier refused, taking the burden of responsibility upon himself.

The letter leaked to the media, and days later, the captain was relieved of his command.

As of Sunday, the number of sailors aboard the USS Theodore Roosevelt that have tested positive for the coronavirus has risen to 585. Crozier is among them and is battling the virus in the "distinguished visitors quarters" on Naval Base Guam, according to The New York Times.

One sailor has been hospitalized and is still in intensive care.

The Navy revealed Sunday that 3,967 sailors, more than 80% of the carrier's crew of 4,800, have been moved ashore in Guam. The Navy has made it clear that it does not intend to remove all of the sailors from the ship, as some are required to stay behind to maintain and operate essential systems.