Sailors aboard the USS Theodore Roosevelt aircraft carrier cheered for Capt. Brett Crozier as he disembarked the ship for the last time, in an overwhelming show of support for their leader who was relieved of his command after issuing a stark warning about a coronavirus outbreak onboard.

New video obtained by CNN shows a large crowd gathered to give Crozier a warm and loud send off, clapping and chanting his name as he left the ship. It was a clear expression of appreciation for their former commander who was removed for what the acting Navy Secretary called "poor judgment."

"Today at my direction the commanding officer of the USS Theodore Roosevelt, Captain Brett Crozier, was relieved of command by carrier strike group commander Rear Admiral Stewart Baker," acting Secretary of the Navy Thomas Modly announced on Thursday.

The decision came days after Crozier wrote a memo warning Navy leadership that decisive action was needed to save the lives of the ship's crew. "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," it read, three US defense officials confirmed to CNN.

News of Crozier's removal comes after a U.S. defence official told CNN Friday morning that 137 sailors from the Roosevelt have tested positive for the virus, representing more than 10% of all cases across the U.S. military.

Escalating outbreak

The outbreak on the ship is escalating rapidly. Last week the Pentagon confirmed three sailors on the Roosevelt had tested positive, and that number had risen to 25 two days later. It rose to at least 70 on Tuesday and more than 100 on Thursday. On Monday, a U.S. defence official told CNN that a second U.S. aircraft carrier, the USS Ronald Reagan, is facing a "handful" of positive cases.

In his memo, Crozier implored Navy leaders to take immediate steps to address the situation.

"Decisive action is required. Removing the majority of personnel from a deployed U.S. nuclear aircraft carrier and isolating them for two weeks may seem like an extraordinary measure," his memo said.

"This is a necessary risk. It will enable the carrier and air wing to get back underway as quickly as possible while ensuring the health and safety of our Sailors. Keeping over 4,000 young men and women on board the TR is an unnecessary risk and breaks faith with those Sailors entrusted to our care," Crozier added.

But despite saying Thursday that Crozier was right to raise his concerns, Modly told reporters that the captain was removed for showing "extremely poor judgment" and creating a "firestorm" by too widely disseminating the memo detailing his concerns, copying some 20 to 30 people.

He said Crozier was not removed because of any evidence suggesting he leaked the memo to the press, but rather for allowing "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."

"I have no information nor am I trying to suggest that he leaked the information. It was published in the San Francisco Chronicle. It all came as a big surprise to all of us that it was in the paper, and that's the first time I had seen it," he added.

Those who know Crozier, like retired Cmdr. Guy Snodgrass, who commanded a squadron of F-18s deployed to the USS Ronald Reagan when Crozier served as that ship's executive officer, say the now dismissed captain would not have written the letter were he not alarmed for the health and welfare of those under his command and their families.

"He cares about the health and welfare of his Sailors first and foremost, Snodgrass said. "A commanding officer would easily conclude that if his or her actions resulted in an accelerated response to what was judged to be a rapidly deteriorating situation, then the relief from command was easily worth it."

Modly on Thursday also acknowledged Crozier's popularity among the aircraft carrier's crew.

"I am entirely convinced that your Commanding Officer loves you, and that he had you at the center of his heart and mind in every decision that he has made. I also know that you have great affection, and love, for him as well," he said.