Editor's Note: A full Oversight Committee hearing was planned for Thursday. It has been rescheduled for Thu., Sept. 13.

A new report finds Republican legislators blocked a credible investigation of the Trump administration's response to the hurricanes that ravaged the country last year, specifically the one that struck Puerto Rico. House Democrats accuse Oversight Committee Chairman Rep. Trey Gowdy, R-South Carolina, of failing to conduct a "fact-based investigation of what went wrong and who was responsible."

House Democrats also said the Republican response was to "insulate President Trump and his aides from scrutiny" and "disregard the lessons learned after Hurricane Katrina."

Hurricane Maria struck Puerto Rico on Sept. 20, 2017, and an estimated 2,975 deaths have been attributed to the storm -- a death toll that was significantly higher than first reported by Puerto Rican officials, the White House and Mr. Trump himself.

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In Oct. 2017, President Trump praised his administration's response to Hurricane Maria's aftermath, saying it was "unbelievable," "amazing" and "incredible." He eventually took to Twitter, writing, "Nobody could have done what I've done for Puerto Rico with so little appreciation."

The House Democrats' report details the disparity between the oversight of Hurricane Katrina and Hurricane Maria, saying Gowdy held no full Committee hearings and didn't request documents from the White House. They claim the Oversight Committee was "unable to adequately investigate key questions about the Trump administration's response, such as the delay in appointing a commanding general, the apparent lack of presidential engagement and direction, the failure to lead a coordinated response and the wavering commitment to recovery and rebuilding."

Gowdy's Republican predecessor, Oversight Committee Chairman Tom Davis, led an investigation of the Bush administration's response to Hurricane Katrina. He held nine hearings, conducted scores of interviews and received dozens of briefings from federal officials and others, the Oversight Committee report said.

There is a full Oversight Committee hearing planned Sept. 6 -- the first one called by Gowdy -- despite multiple requests from Democratic members. Nearly a year ago, on Sept. 29, 2017, Ranking Member Rep. Elijah Cummings, D-Maryland, and Rep. Stacey Plaskett, the Ranking Member of the Subcommittee on the Interior, Energy and Environment, sent a letter to Gowdy requesting a hearing. Democrats on the Committee said the request was ignored, but a spokeswoman for Gowdy pointed to the fact that two subcommittee hearings were held: a field hearing in the U.S. Virgin Islands on March 12, 2018, held by the Subcommittee on Interior, Energy and Environment, and a hearing March 21, 2018, held by the Subcommittee on National Security.

"The Committee has also held numerous briefings with the Department of Homeland Security (including FEMA), Department of Defense (including the United States Army Corps of Engineers), Health and Human Services and the Government Accountability Office," Gowdy's office said. "The Committee's investigation is ongoing, and we are continuing to receive document productions."

Late Wednesday night, Federal Emergency Management Agency (FEMA) Administrator Brock Long said he won't be able to attend Thursday's hearing because of "three hurricanes potentially threatening United States' interests, for which FEMA needs to prepare."

When Davis issued his final report on Hurricane Katrina, he wrote, "Government failed because it did not learn from past experiences, or because lessons thought to be learned were somehow not implemented. If 9/11 was a failure of imagination, then Katrina was a failure of initiative. It was a failure of leadership."

The report says -- more than a decade later -- the Oversight's Committee's investigation of the Trump administration's response to the hurricanes in Puerto Rico and the U.S. Virgin Islands not only ignored these lessons from the past, but added a new failure of its own: A failure of oversight.

The House Democrats' report comes on the heels of another report in August that said Hurricane Maria is now considered the most deadly U.S. natural disaster in the last century. Puerto Rico's government requested an independent review by George Washington University, which found Maria killed an estimated 2,975 people – more than 46 times the original official death toll of 64.

For months, there's been speculation the death toll was much higher than what the government was reporting. San Juan's mayor, Carmen Cruz, called the new report "painful and shameful," and told CBS News' David Begnaud the governor should take more responsibility.

"When I saw people dying I opted to shout it. I opted to ask for help. When others saw people dying they opted to shut up," Cruz said.

Puerto Rico Gov. Ricardo Rosselló acknowledged Aug. 29 he made mistakes.

"The focus shouldn't be, you know, hey, let's blame all these folks. The focus should be who's going to be accountable and who's going to take the action so this doesn't happen again," Rosselló said.

Researchers found the government and hospitals were inadequately prepared for the Category 4 storm. They also found the risk of death was 45 percent higher for those living in low-income areas on the island, and elderly men were at the greatest risk of dying.

Editor's Note: This article was updated to include a response from Gowdy's office and clarification over subcommittee hearings that were held about Hurricane Maria's response.