Inside the Osama bin Laden Strike: How America Got Its Man

Osama bin Laden's final night began with a group of four helicopters slicing through the night skies over Pakistan, making their way toward Islamabad from a U.S. base in northern Afghanistan. The mission, approved by President Barack Obama on Friday morning, had been set for early Sunday local time but was delayed by poor weather. Pakistani officials did not know they were arriving. The small, elite force flew low and fast, using terrain-following radar to hug the folds and valleys to avoid radar detection. It was after midnight when the team of U.S. commandos descended on the al-Qaeda chief's Abbottabad lair.

"The walls around the compound were up to 18 ft. [5.5 m] high," a senior U.S. intelligence operative said Monday. "The balconies had 7-ft. [2 m]-high privacy walls. There were, in addition to wall heights, barbed wire along the top of the walls. The residents of the compound burned their own trash. There were two gates at the compound as well, and opaque windows," he continued. The White House summed it up more tersely. "It had the appearance of sort of a fortress," said John Brennan, Obama's chief counterterrorism adviser.

About two dozen Navy Seals and CIA enablers swooped down on the suburban compound in a pair of choppers, leaving a second pair lurking nearby in case they were needed. They came under fire almost immediately, giving U.S. forces all the justification they needed to amp up their firepower. Helicopters can be ungainly machines, easily downed by rocket-propelled grenades or a flurry of small-arms fire. In addition to the choppers, heavier guns — perhaps AC-130 gunships — were likely on station overhead to rain down suppressive fire as U.S. forces moved in aboard specially outfitted CH-47 and UH-60 choppers.

Seven thousand miles away, U.S. officials could only watch as the operation unfolded. At the White House, Obama sat stone-faced in the Situation Room as some of his aides paced. Long periods of silence passed as the small, trusted national-security team huddled around the video monitors. Intelligence professionals say they did not know for sure that bin Laden was in the compound. The case was good, but circumstantial. The likelihood, officials told the President, was between 50% and 80%.

Senior Administration officials said they had been monitoring the compound since August 2010, when a courier known to be trusted by bin Laden, as well as the courier's brother, began living there. "Everything we saw — the extremely elaborate operational security, the brothers' background and their behavior, and the location and the design of the compound itself — was perfectly consistent with what our experts expected bin Laden's hideout to look like," one official said early Monday. "Our analysts looked at this from every angle, considering carefully who other than bin Laden could be at the compound. We conducted red-team exercises and other forms of alternative analysis to check our work. No other candidate fit the bill as well as bin Laden did."

Early discussion of bombing the compound was scrapped in favor of a snatch and grab — the U.S. wanted bin Laden's body as evidence of his demise. Even in a bombing mission, U.S. or allied personnel would have had to go to the compound for evidence. It made more sense, although it was riskier, to raid the place and get bin Laden, dead or alive. "The men who executed this mission accepted this risk, practiced to minimize those risks and understood the importance of the target to the national security of the United States," a senior Administration official said.

And so they went in. Twenty-four Seals fast-roped to the ground; a total of about 80 U.S. personnel took part, either in the air or below. One helicopter lost lift because the compound's high walls upset its supporting airflow, forcing it to make a hard landing. The commandos elected to destroy the helicopter rather than try to recover it: time was short. The Seals fired hundreds of rounds as they blasted their way into the compound, clearing it room by room, until the top two floors of the main three-story building were the only areas left to be cleared.

Midway through the 40-minute mission, Pakistani military forces began scrambling to investigate the attack — U.S. officials feared a clash between the U.S. troops and their unknowing Pakistani allies. And as the Seals moved through the compound, authorities back in Washington began to sweat. "It was probably one of the most anxiety-filled periods of time, I think, in the lives of the people who were assembled here yesterday," Brennan said Monday. "The minutes passed like days ... it was clearly very tense, a lot of people holding their breath." The gunfire was almost ceaseless.

A woman, in some accounts believed to be one of bin Laden's wives, was shot. "She fought back when there was the opportunity to get to bin Laden," Brennan said of the lone woman who died in the raid. "She was positioned in a way that indicated that she was being used as a shield, whether or not bin Laden or the son or whatever put her there, or she put herself there ... she met her demise."

Then it happened. Back at the White House, a disembodied voice radioed, "We've ID'd Geronimo," referring to the agreed-upon code name for America's most wanted enemy. And then confirmation: Geronimo, Osama bin Laden, had been killed. It was 1 a.m. in Pakistan. No American casualties had been sustained. The three remaining helicopters took off bearing the commando team and the body of the slain al-Qaeda chief.

After undergoing DNA verification in Afghanistan, bin Laden's remains were flown to the U.S.S. Carl Vinson aircraft carrier. The body was washed, wrapped in a white sheet and placed in a weighted bag. A military official read a few religious passages in Arabic. And then, less than 24 hours after his death, and nearly a decade after the manhunt began, bin Laden's body slipped into the North Arabian Sea.

— With reporting by Michael Scherer / Washington