WASHINGTON — Active-service members and veterans provided firsthand testimony Wednesday about the chaotic U.S. withdrawal from Afghanistan, describing in harrowing detail the carnage and death they witnessed on the ground while imploring Congress to help the allies left behind.

Former Marine Sgt. Tyler Vargas-Andrews testified to Congress about the stench of human flesh under a large plume of smoke as the screams of children, women and men filled the space around Kabul’s airport after two suicide bombers attacked crowds of Afghans.

“The withdrawal was a catastrophe in my opinion. And there was an inexcusable lack of accountability,” said Vargas-Andrews, who wore a prosthetic arm and scars of his own grave wounds from the bombing.

“I see the faces of all of those we could not save, those we left behind,” Aidan Gunderson, an Army medic who was stationed at Abbey Gate, testified. “I wonder if our Afghan allies fled to safety or they were killed by the Taliban.”

The initial hearing of a long-promised investigation by House Republicans displayed the open wounds from the end of America’s longest war in August 2021, with witnesses recalling how they saw mothers carrying dead babies and the Taliban shooting and brutally beating people.

It was the first of what is expected to be a series of Republican-led hearings examining the Biden administration’s handling of the withdrawal. Taliban forces seized the Afghan capital, Kabul, far more rapidly than U.S. intelligence had foreseen as American forces pulled out. Kabul’s fall turned the West’s withdrawal into a rout, with Kabul’s airport the center of a desperate air evacuation guarded by U.S. forces temporarily deployed for the task.

The majority of witnesses argued to Congress that the fall of Kabul was an American failure with blame touching every presidential administration from George W. Bush to Joe Biden. Testimony focused not on the decision to withdraw, but on what witnesses depicted as a desperate attempt to rescue American citizens and Afghan allies with little U.S. planning and inadequate U.S. support.

“America is building a nasty reputation for multi-generational systemic abandonment of our allies where we leave a smoldering human refuse from the Montagnards of Vietnam to the Kurds in Syria,” retired Lt. Col. Scott Mann testified before the House Foreign Affairs Committee.

He added, “Our veterans know something else that this committee might do well to consider: We might be done with Afghanistan, but it’s not done with us.”

Vargas-Andrews sobbed as he told lawmakers of being thwarted in an attempt to stop the single deadliest moment in the U.S. evacuation — a suicide bombing that killed 170 Afghans and 13 U.S. servicemen and women.

Vargas-Andrews said Marines and others aiding in the evacuation operation were given descriptions of men believed to be plotting an attack before it occurred. He said he and others spotted two men matching the descriptions and behaving suspiciously, and eventually had them in their rifle scopes, but never received a response about whether to take action.

“No one was held accountable,” Vargas-Andrews told Rep. Mike McCaul, R-Texas, the chairman of the committee. “No one was, and no one is, to this day.”

U.S. Central Command’s investigation concluded in October 2021 that given the worsening security situation at Abbey Gate as Afghans became increasingly desperate to flee, “the attack was not preventable at the tactical level without degrading the mission to maximize the number of evacuees.” However, that investigation did not look into whether the bomber could have been stopped or whether Marines on the ground had the appropriate authorities to engage.

Defense Department spokesman Lt. Col. Rob Lodewick said Wednesday that the Pentagon’s earlier review of the suicide attack had turned up neither any advance identification of a possible attacker nor any requests for “an escalation to existing rules of engagement” governing use of force by U.S. troops.

McCaul has been deeply critical of the Biden administration’s handling of the withdrawal. “What happened in Afghanistan was a systemic breakdown of the federal government at every level, and a stunning failure of leadership by the Biden administration,” he said.

Last month, U.S. Inspector-General for Afghanistan John Sopko concluded again that actions taken by both the Trump and Biden administrations were key to the sudden collapse of the Afghan government and military, even before U.S. forces completed their withdrawal in August 2021.

That includes President Donald Trump’s one-sided withdrawal deal with the Taliban, and the abruptness of Biden’s withdrawal of both U.S. contractors and troops from Afghanistan, stranding an Afghan air force that previous administrations had failed to make self-supporting.

The report blamed each U.S. administration since American forces invaded in 2001 for constantly changing, inconsistent policies that strived for quick fixes and withdrawal from Afghanistan rather than a steady effort to build a capable, sustainable Afghan military.

The witnesses testifying Wednesday urged action to help the hundreds of thousands of Afghan allies who worked alongside U.S. soldiers and who are now in limbo in the U.S. and back in Afghanistan.

“If I leave this committee with only one thought it’s this: It’s not too late,” said Peter Lucier, a Marine veteran who now works at Team America Relief, which has assisted thousands of Afghans in relocating. “We’re going to talk a lot today about all the mistakes that were made, leading up to that day, but urgent action right now will save so many lives.”

One of those solutions discussed Wednesday would be creating a pathway to citizenship for the nearly 76,000 Afghans who worked with American soldiers since 2001 as translators, interpreters and partners. Those people arrived in the U.S. on military planes after the withdrawal and the government admitted the refugees on a temporary parole status as part of Operation Allies Welcome, the largest resettlement effort in the country in decades, with the promise of a path to a life in the U.S. for their service.

Congress began a bipartisan effort to pass the Afghan Adjustment Act, which would have prevented Afghans from becoming stranded without legal residency status when their two years of humanitarian parole expire in August. The proposal would have enabled qualified Afghans to apply for U.S. citizenship, as was done for refugees in the past, including those from Cuba, Vietnam and Iraq.

But that effort stalled in the Senate late last year due to opposition from Republicans.

“If we don’t set politics aside and pursue accountability and lessons learned to address this grievous moral injury on our military community and right the wrongs that have been inflicted on our most at-risk Afghan allies, this colossal foreign policy will follow us home and ultimately draw us right back into the graveyard of empires where it all started,” Mann, the retired green beret, said to lawmakers.