American officials insisted they would have taken Bin Laden into custody if he did not resist, although they considered that likelihood remote. “If we had the opportunity to take Bin Laden alive, if he didn’t present any threat, the individuals involved were able and prepared to do that,” Mr. Brennan said.

One of Bin Laden’s wives identified his body, American officials said. A picture taken by a Seals commando and processed through facial recognition software suggested a 95 percent certainty that it was Bin Laden. Later, DNA tests comparing samples with relatives found a 99.9 percent match.

But the Americans faced other problems. One of their helicopters stalled and could not take off. Rather than let it fall into the wrong hands, the commandos moved the women and children to a secure area and blew up the malfunctioning helicopter.

By that point, though, the Pakistani military was scrambling forces in response to the incursion into Pakistani territory. “They had no idea about who might have been on there,” Mr. Brennan said. “Thankfully, there was no engagement with Pakistani forces.”

As they took off at 1:10 a.m. local time, taking a trove of documents and computer hard drives from the house, the Americans left behind the women and children. A Pakistani official said nine children, from 2 to 12 years old, are now in Pakistani custody.

The Obama administration had already determined it would follow Islamic tradition of burial within 24 hours to avoid offending devout Muslims, yet concluded Bin Laden would have to be buried at sea, since no country would be willing to take the body. Moreover, they did not want to create a shrine for his followers.

So the Qaeda leader’s body was washed and placed in a white sheet in keeping with tradition. On the aircraft carrier Carl Vinson, it was placed in a weighted bag as an officer read prepared religious remarks, which were translated into Arabic by a native speaker, according to the senior Pentagon official.

The body then was placed on a prepared flat board and eased into the sea. Only a small group of people watching from one of the large elevator platforms that move aircraft up to the flight deck were witness to the end of America’s most wanted fugitive.