The witnesses, speaking at a House Foreign Affairs Committee hearing, recounted their experiences during the evacuation, some as active-duty service members who scrambled to Kabul after the militant group seized power Aug. 15, 2021, and others as volunteers who sought to help desperate Afghans from afar.

“The withdrawal was a catastrophe, in my opinion, and there was an inexcusable lack of accountability and negligence,” said Marine Sgt. Tyler Vargas-Andrews, whose powerful, painful testimony about a suicide bombing on the outskirts of the city’s airport left him overcome with emotion and, at times, unable to speak. The attack resulted in the deaths of nearly 200 people, including 13 American service members, and the loss of two of his limbs.

“The 11 Marines, one sailor and one soldier [killed] that day have not been answered for,” he told lawmakers.

House Republicans called Wednesday’s hearing as part of their broadening scrutiny of the Biden administration’s decision-making during the evacuation, an operation hastily formed as the U.S.-backed Afghan government collapsed. Afghans overran Hamid Karzai International Airport, desperate to flee the regime that ruled their country so ruthlessly before U.S.-led forces removed it from power 20 years earlier. The airfield became ground zero for a crisis that unfolded over the following two weeks, with more than 124,000 people flown to safety but with thousands of others effectively stranded behind enemy lines.

Lawmakers foreshadowed additional hearings — and more partisan fighting — over where to assign blame for the staggering failures that occurred as the war came to a tragic close.

Rep. Michael McCaul (R-Tex.), the committee chairman, opened the hearing by declaring the evacuation effort “disastrous.” While the Defense Department and U.S. intelligence community issued grim assessments of what could happen before Kabul fell, McCaul said, the White House and the State Department “consistently painted a rosier picture, ignoring the realities on the ground.”

McCaul said it is “certainly the game plan” to seek the testimony of President Biden’s top national security advisers, including Secretary of State Antony Blinken, Defense Secretary Lloyd Austin and Gen. Mark A. Milley, chairman of the Joint Chiefs of Staff.

Democrats acknowledged Wednesday that mistakes were made, but they quickly cast blame on Biden’s predecessor, former president Donald Trump, who, they noted, approved pursuing negotiations with the Taliban and ultimately struck the deal in 2020 that required U.S. forces to depart the following year.

“Any fair analysis of the events of this withdrawal have to include all of the context, and not recognizing that reality is disingenuous and taints with partisanship something that should be bipartisan,” Rep. Colin Allred (D-Tex.) said.

At peak disorder during the withdrawal, thousands of Afghans clogged the streets outside the airfield as U.S. military personnel and Taliban foot soldiers, in a hastily reached agreement, sought to enforce order. But the two sides displayed drastically different approaches. U.S. troops have described witnessing beatings — even executions — as they maintained security, but they were ordered not to intervene.

Three days after the bombing, U.S. military personnel carried out a drone strike on a compound near the airport and initially claimed to have killed a potential second suicide bomber. But after days of questions about the strike, U.S. officials acknowledged that they had made a mistake and instead struck an Afghan family, killing three adults and seven children. Those deaths did not come up on Wednesday.

Other witnesses included Aidan Gunderson, a former Army specialist who left active duty in July, and three military veterans involved with the ad hoc effort to help identify and locate allied Afghans. They were Francis Q. Hoang of Allied Airlift 21, Peter Lucier of Team America Relief and Scott Mann of Task Force Pineapple.

They were joined by Camille Mackler, executive director of the Immigrant Advocates Response Collaborative, which has assisted Afghans resettling in the United States.

Gunderson called the withdrawal an “organizational failure at multiple levels,” telling lawmakers that he and fellow soldiers with the 82nd Airborne Division arrived at the airport the night Kabul fell with few supplies and security in disarray. They encountered unruly, surging crowds and the blood-soaked remains of Afghans who had plummeted to their deaths after clinging to departing U.S. aircraft in attempts to escape.

“Departing on August 31st on one of the last flights out of the country, I was relieved to be headed home, but I wondered how the horror I just witnessed had just changed me — how it would change us all,” Gunderson said. “I can assure that it has. This war is not over for millions of people in Afghanistan and the U.S. Thoughts of those two weeks have plagued my mind since coming home. I see the faces of all the people we could not save. All the people we left behind.”

Vargas-Andrews, recounting an episode he shared with The Washington Post in an extensive interview last year, said that on the day of the airport bombing, he and another Marine spotted from a guard tower two individuals who matched the description of potential suicide bombers. They sought commanders’ permission to shoot the men and neutralize the threat but were denied, he said, adding that no government official investigating the attack had ever asked him about his experiences.

“It makes me feel like my service is not valued,” Vargas-Andrews said, clarifying at the outset of his testimony that he was appearing in his personal capacity, and not representing his service.

Mann, a retired Special Forces officer, told the committee that the United States is developing a “nasty reputation” for abandoning wartime allies. His voice cracking, he said a friend of his was found dead in a Mississippi hotel room some months after the collapse in Afghanistan “reactivated all of the demons that he had managed to put behind him.” Many veterans, he said, continue to cope with moral injury from the war and its calamitous end.

“This whole thing has been a gutting experience,” Mann said. “I never imagined I would witness the kind of gross abandonment, followed by career-preserving silence, of senior leaders, military and civilians.”

Hoang, who came to the United States as a refugee in 1975 after the fall of Vietnam, and other witnesses advocated for lawmakers to expand the size and scope of the special immigrant visa program that allows many Afghans who assisted the U.S. war effort to come to the United States.

“I think that there is a tremendous need to enable the executive branch to increase both the throughput and capacity to process those visas and transport the people who have been granted a visa or approval for a visa out of Afghanistan posthaste,” said Hoang, who served in the Army.

He added that the State Department found itself in a difficult position during the evacuation “with very little guidance as far as we can tell” and “hamstrung by the bureaucracy.”

Lucier, a Marine Corps veteran who served in Afghanistan from 2011 to 2012, said his biggest question is what will happen to the 72,000 Afghans now in the United States through temporary humanitarian parole but who have no legal right to stay longer unless Congress passes legislation.

One path would be to pass the Afghan Adjustment Act, bipartisan legislation halted by Senate Republicans last year. Mackler, an immigration attorney, said that unless the bill is passed, the Afghans in question will be subject to deportation.

Near the hearing’s end, Rep. Gregory W. Meeks (N.Y.), the committee’s top Democrat, said that the United States extricating itself from a 20-year “quagmire” always was going to be a difficult task.

“There were successes in this operation, and there were mistakes. And we’ve acknowledged both,” he said. “I believe we are deluding ourselves if we believe that this could have been an easy operation, given the deteriorating security situation and rapidly changing events on the ground that no one could have predicted.”

McCaul described the evacuation as a “dark chapter” in American history, and he encouraged anyone with information about the missteps involved to come forward.

“We simply want to get the truth out,” he said.

McCaul concluded the hearing by turning to Vargas-Andrews and saying that his testimony about the suspected suicide bomber slipping away illustrates the need for accountability.

“That’s probably one of the saddest things out of this hearing,” McCaul said, “and we pray for you and all the veterans out there.”