In a letter sent to the committee Wednesday night, Federal Emergency Management Agency Administrator Brock Long said he would be unable to attend the hearing, citing that the proceedings had been postponed multiple times, and conflicted with agency's work during the ongoing hurricane reason.
The Puerto Rican government recently raised the death toll from Hurricane Maria to 2,975 from 64, following the release of a report on the death toll from independent researchers contracted by the government.
The Government Accountability Office, a federal watchdog, also released a report on Tuesday detailing FEMA's struggles to respond to the hurricanes, concluding that the overstretched agency faced challenges that slowed its efforts to respond to Hurricane Maria.
The report compares the committee's review of the government's hurricane response to the investigation conducted by former GOP committee chairman Tom Davis into the Bush administration's actions after Hurricane Katrina.
Davis' five-month probe, Democrats said, produced hundreds of thousands of pages of documents from across the White House and administration and a 569-page report faulting the Bush administration, state officials and private contractors.
"More than a decade later, the Oversight 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," Democrats wrote in their report.
In response, a committee aide said that the panel has been in contact with FEMA on a "near-weekly" basis and has reviewed more than 16,500 pages of documents from various government agencies.
The committee also has conducted field hearings and staff trips to survey response efforts in Puerto Rico, Texas and the U.S. Virgin Islands, and held briefings with government officials and requested documents from the Department of Homeland Security, the Pentagon and the Department of Health and Human Services.