A member of the Senate Armed Services Committee on Tuesday called on Navy officials to provide hard data showing they have improved conditions on their ships in the months since two destroyers were involved in back-to-back collisions that left 17 sailors dead.

The senator, Angus King of Maine, made the demand of Adm. Philip Davidson, the top military commander in the Pacific, days after ProPublica published an investigation into the deadly mishaps in 2017, the Navy’s worst accidents at sea in four decades. The investigation showed that the Navy’s most senior leaders, uniformed and civilian, had failed to act on repeated warnings that the 7th Fleet, based in the Pacific and renowned as the largest armada in the world, was at risk — its sailors poorly trained and overworked, its ships in physical decline.

The Navy since the accidents has pledged a host of reforms, from improved staffing to better training.

“I want real numbers. I don’t want general ‘We’re working on staffing’ or ‘We’re working on more training,’ because these were avoidable tragedies,” King, an independent who caucuses with Democrats, said during a Senate Armed Services Committee hearing. “I would like to see specific responses from the Navy. Not promises and not good feelings.”

Davidson was in charge of ensuring that the Navy’s fleets were properly manned at the time of the collisions, and he personally drafted a reform plan. He praised the Navy’s track record by pointing out that most ships were not colliding.

“The fact of the matter is 280-odd other ships weren’t having collisions,” Davidson said. “More than a dozen of those ships were performing exceptionally well.”

King interrupted Davidson.

“Airplanes are landing all over America, and just because they aren’t all crashing doesn’t mean they don’t need a high level of maintenance,” he said. “To tell me that isn’t very convincing. I think it was 40 years since we’d had collisions of this nature. Are you saying that there were no failures that led to these collisions because there were 280 ships that didn’t have collisions? Isn’t that the standard? No collisions?”

Davidson said he had read the first installment of ProPublica’s investigation, which detailed what went wrong on the USS Fitzgerald in the first of the two accidents. But he said he had not read the second installment, which laid out the years of warnings made by sailors on the decks of ships, commanders and top civilians officials in Washington about the state of the Navy’s ships before the crashes.

King urged him to read it.

“It’s one of the most sobering analyses of a disaster that I’ve ever seen,” King said. “And it takes responsibility all the way through the very top of the Navy to this Congress.”

“There were multiple warnings, it wasn’t acted upon and I want to be reassured that it is being acted upon,” King said.

Davidson was appearing to help brief the Armed Services Committee on military operations in the Pacific, and the latest assessment of threats posed by China and North Korea, among other countries.

Davidson agreed to provide the data King was asking for on ship maintenance, staffing levels and crew training, but he said the Navy has already been providing Congress with quarterly updates on improvements.

He also defended the Navy’s efforts to fix problems in its 7th Fleet, based in Japan. The Navy has said it has completed 80 percent of more than 100 reforms developed in the aftermath of the tragedies. Navy officials have declined to provide specifics to ProPublica.

“I’ve been quite pleased with the progress the Navy’s made,” Davidson said.

The Navy’s updates have come mostly in the form of oral briefings, behind closed doors at the Navy’s request, that have focused more on a discussion of reforms and anecdotal improvements — and have been short on hard readiness data that Congress can use to see trends over time, an aide to the House Armed Services Committee said.

“They’re not even reports,” the aide said.

The Navy did not immediately respond to a request for comment.