The details of the United States' special forces raid on the top leader of the Daesh terrorist group, known as Abu Ibrahim al-Hashimi al-Qurayshi, in northwestern Syria early Thursday, have begun to emerge.

U.S. forces rehearsed the helicopter raid over and over, hoping to capture Daesh's leader on the third floor of a residential building in a Syrian town near the Turkish border, where he was holed up with his family.

But before they could reach him, al-Qurayshi detonated a suicide bomb, triggering a large explosion that blew mangled bodies – including his own – out of the building into the streets outside.

When U.S. commandos thumped onto the ground in Syria an hour after midnight, the raiders confronted a houseful of extremists and children. Baby comforts were inside – a stuffed bunny, a blue plastic swing, a crib. So was the paraphernalia of violence – such as the bomb al-Qurayshi is said by U.S. officials to have used to blow up himself, his family and perhaps others in his immediate proximity.

U.S. President Joe Biden, who monitored the raid from the White House's Situation Room, called al-Qurayshi's suicide a "final act of desperate cowardice." It echoed the self-detonation of a bomb by his predecessor, Daesh founder Abu Bakr al-Baghdadi, during a U.S. raid in 2019 in Syria.

For residents in the town of Atmeh, the events were terrifying, as U.S. forces swept in aboard helicopters before trying to evacuate civilians from the cinder-block building, using loudspeakers to tell them to leave.

"Men, women and children raise your hands. You are in safety of the American coalition that is surrounding the area. You will die if you don't get out," said one woman recounting the U.S. warnings.

Marine Gen. Frank McKenzie, who oversees U.S. forces in the region and was providing updates to Biden, said U.S. troops got six civilians, including four children, to leave the first floor of the building before the blast ripped apart the top floor.

"The explosion, which was more massive than would be expected from a suicide vest, killed everyone on the third floor and in fact ejected multiple people from the building," McKenzie said, adding that al-Qurayshi, his wife and two children died.

A second U.S. official later said two of al-Qurayshi's wives and one child were killed.

As U.S. troops advanced to the second floor, one of al-Qurayshi's lieutenants and his wife started firing on the Americans and were killed. One child was found dead there, McKenzie said, and three other children and an infant were brought to safety from the second floor.

Syrian rescue workers said at least 13 people died, most of them women and children.

The Pentagon said at least two armed members of a local al-Qaida affiliate were killed by gunfire from a U.S. helicopter after they approached the scene of the raid, while U.S. troops were still at the site.

Target on third floor

U.S. officials said al-Qurayshi's death was another setback for a group that once ruled a self-proclaimed caliphate stretching across territory in Syria and Iraq. It is now waging insurgent attacks.

Planning for the operation began in early December when officials became convinced the Daesh leader was living in the building, the officials said. Biden received a detailed briefing on options for capturing al-Qurayshi alive on Dec. 20, a senior White House official said.

One official said the operation was complicated by the fact that al-Qurayshi rarely left his residence on the building's third floor and relied on couriers to interact with the outside world.

The number of children seen in the area and families believed to be living on the first floor led U.S. officials to try to craft a mission aiming to safeguard civilians, they said.

That ultimately required putting U.S. forces at risk in a raid, instead of launching a remote strike, the officials said.

U.S. military procedures to guard against civilian casualties are under scrutiny following a high-profile mistaken drone strike in Kabul during the U.S. evacuation of civilians from Afghanistan that the Pentagon initially hailed a success.

The Pentagon said it would review all the information from the Atmeh raid to ensure no civilians were harmed by U.S. forces but stressed all indications so far were that civilian deaths were caused by Daesh fighters themselves.

Biden gave final approvals for the mission on Tuesday during an Oval Office meeting with Defense Secretary Lloyd Austin and Gen. Mark Milley, who as chairperson of the Joint Chiefs of Staff is the top American military officer, U.S. officials said.

Biden, Vice President Kamala Harris and other administration officials received real-time updates from Austin, Milley and McKenzie as they watched the operation unfold on several screens from the Situation Room, the officials said.

Biden joined the group in the Situation Room around 5 p.m. ET on Wednesday after finishing a call with French President Emmanuel Macron on an unrelated topic, the White House official said.

At one point, a helicopter involved in the raid suffered a mechanical failure and had to be destroyed rather than left behind, the Pentagon said.

Biden said "God bless our troops" once U.S. forces were wheels up after the operation, and kept tabs on them during the night as they flew to safety, officials said.

Once U.S. forces were in safety, Biden reflected on an airstrike carried out in 2015 – when he was serving as vice president – that killed another Daesh leader and injured al-Qurayshi, costing him a leg, the White House official said.

Milley told Biden that U.S. forces hit "a visual ID jackpot" when they viewed al-Qurayshi's body and confirmed his identity using biometric data taken from a fingerprint during the flight back, the official said. They waited to announce his death until after a DNA test was completed, the official added.

"He was on our target list from the earliest days of the campaign. He was Baghdadi's right-hand man, and ... was personally responsible for some of the most vicious Daesh atrocities," the official.