WASHINGTON, April 5 (Xinhua) -- Captain Brett Crozier, who has commanded aircraft carrier USS Theodore Roosevelt until his recent removal by the Navy for sounding the alarm about a coronavirus outbreak on board, has tested positive for the virus, The New York Times reported on Sunday.

The Times, citing Crozier's Naval Academy classmates, said Crozier exhibited symptoms before he was relieved of his duty on the warship Thursday.

Secretary of Defense Mark Esper said Sunday an investigation into Crozier's actions is ongoing. "All the services at times relieve commanders without the benefit of an investigation up front because they've lost confidence in them. It's certainly not unique to the Navy," he said on CNN's "State of the Union" program.

The secretary also confirmed that there have been 155 positive tests among sailors on board the Roosevelt, that more than half of the crew have been tested, and that there have been no hospitalizations.

The Navy planned to evacuate 2,700 of the roughly 5,000 crew members on the vessel, leaving the rest on board to maintain the ship's operation. As of Saturday, 1,548 service members have disembarked the ship, and The Times, citing local hotel association, said at least an additional 400 service members will be moved to Guam hotels Sunday.

Crozier sent a five-page internal letter earlier this week to higher-ranking officials in the chain of command, pleading for help from the Pentagon to contain a COVID-19 outbreak aboard the Roosevelt by transferring 90 percent of the crew onto Guam for quarantine. The ship now docks in Guam.

"We are not at war," the captain wrote in the letter, which was first made public by the San Francisco Chronicle. "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."

Crozier's ousting was announced Thursday by Acting Navy Secretary Thomas Modly, who said the captain allowed "the complexity of his challenge with the COVID breakout on the ship to overwhelm his ability to act professionally when acting professionally was what was needed the most at the time."

"In sending it out pretty broadly, he did not take care to ensure that it couldn't be leaked," Modly said. "And that's part of his responsibility."

President Donald Trump said Saturday that he supported Crozier's firing, adding "it was terrible what he did."

The Democrats, however, condemned the Navy. Democratic lawmakers in both the Senate and the House asked for a probe into the matter.

Immediately following Crozier's ouster Thursday, the Democratic leaders of the House Armed Services Committee issued a statement condemning his removal. "Captain Crozier was justifiably concerned about the health and safety of his crew, but he did not handle the immense pressure appropriately," the lawmakers said, adding that "relieving him of his command is an overreaction."

"Throwing the commanding officer overboard without a thorough investigation is not going to solve the growing crisis aboard the U.S.S. Theodore Roosevelt," they said.

Democratic senators Richard Blumenthal of Connecticut and Chris Van Hollen of Maryland wrote a letter co-signed by 15 of their colleagues Friday to Acting Inspector General for the Department of Defense Glenn Fine, urging him to launch a formal investigation into the Navy's response to the COVID-19 outbreak on the Roosevelt, as well as its decision to fire the captain.

"It is essential that your office conduct a comprehensive investigation to avoid any potential conflicts of interest within the Navy chain of command, and we encourage you to evaluate all relevant matters associated with the dismissal and the outbreak on the ship," they wrote in the letter.

Former Vice President Joe Biden criticized the Navy's actions. "I think it's close to criminal the way they're dealing with this guy," Biden said Sunday on ABC's "This Week," adding that Crozier "should have a commendation rather than be fired."

In a Friday tweet hailing the captain, Biden said Crozier "was faithful to his duty-both to his sailors and his country."

"Navy leadership sent a chilling message about speaking truth to power," the former vice president said. "The poor judgment here belongs to the Trump Admin, not a courageous officer trying to protect his sailors."

In an op-ed carried by The Times on Friday titled "Captain Crozier Is a Hero," Tweed Roosevelt said what Crozier did to protect sailors under his command showed judgment similar to that of Theodore Roosevelt - Tweed's great grandfather and the 26th President of the United States - during the Spanish-American War.

"In this era when so many seem to place expediency over honor, it is heartening that so many others are showing great courage, some even risking their lives. Theodore Roosevelt, in his time, chose the honorable course. Captain Crozier has done the same," Roosevelt wrote.