Published: May 02, 2011 9:59 AM EDT
Updated: May 02, 2011 7:00 AM EDT

WASHINGTON (AP) - Osama bin Laden, the terror mastermind killed by Navy SEALs in an intense firefight, was hunted down based on information first gleaned years ago from detainees at secret CIA prison sites in Eastern Europe, officials disclosed Monday. The U.S. said a DNA match proved the man behind the attacks of Sept. 11, 2001, was dead, and millions of Americans rejoiced.

After the gunfire, U.S. forces swept bin Laden's fortified compound in Pakistan and left with a trove of hard drives, DVDs and other documents that officials said the CIA was already poring over. The hope: clues leading to his presumed successor, al-Qaida No. 2 Ayman al-Zawahiri.

"The world is safer. It is a better place because of the death of Osama bin Laden," declared President Barack Obama, hours after U.S. forces killed the al-Qaida leader. They then ferried the body out for a quick burial at sea.

Bin Laden's death after a decade on the run unloosed a national wave of euphoria mixed with remembrance for the thousands who died in the Sept. 11 2001, terror attacks. Crowds celebrated throughout the night outside the White House and at ground zero in Lower Manhattan where the Twin Towers once stood. Thousands of students at Penn State University and in other college towns spilled into the streets and set off firecrackers to mark the moment.

"For my family and I, it's good, it's desirable, it's right," said Mike Low of Batesville, Ark., whose daughter Sara was a flight attendant aboard the hijacked plane that was flown into the World Trade Center North Tower. "It certainly brings an ending to a major quest for all of us."

Halfway around the world, a prominent al-Qaida commentator vowed revenge for bin Laden's death. "Woe to his enemies. By God, we will avenge the killing of the Sheik of Islam," he wrote under his online name Assad al-Jihad2. "Those who wish that jihad has ended or weakened, I tell them: Let us wait a little bit."

U.S. officials conceded the risk of renewed attack. The terrorists "almost certainly will attempt to avenge" bin Laden's death, CIA Director Leon Panetta wrote in a memo that congratulated the agency for its role in the operation. "Bin Laden is dead. Al-Qaida is not."

Within a few hours, the Department of Homeland Security warned that bin Laden's death was likely to provide motivation for attacks from "homegrown violent extremists" seeking revenge."

FBI spokesman Paul Bresson said, "While there are no specific, bin Laden-related threats at this time, every logical and prudent step is being taken to mitigate any developing threats." There were questions, as well, about Pakistan's role in bin Laden's years in hiding. Both Obama and Secretary of State Hillary Rodham Clinton said cooperation from the Pakistani government had helped lead U.S. forces to the compound where he died.

But John Brennan, White House counter-terrorism adviser, told reporters it was inconceivable that the terrorist fugitive didn't have some support in Pakistan, where his hideout had been custom built six years ago in a city with a heavy military presence. "I am not going to speculate about what type of support he might have had on an official basis," he added.

Others were not as reticent.

Sen. Carl Levin, D-Mich., chairman of the Senate Armed Services Committee, said the Pakistani Army and intelligence agency "have a lot of questions to answer, given the location, the length of time and the apparent fact that this was actually - this facility was actually built for bin Laden, and its closeness to the central location of the Pakistani army."

By their condemnations, bin Laden's supporters confirmed his death in what U.S. officials said was an operation years in the making. Even so, officials were weighing the release of at least one photo taken of bin Laden's body as part of what Brennan called an effort to make sure "nobody has any basis to try and deny" the death.

U.S. officials said the information that ultimately led to bin Laden's capture originally came from detainees held in secret CIA prison sites in Eastern Europe. There, agency interrogators were told of an alias used by a courier whom bin Laden particularly trusted.

It took four long years to learn the man's real name, then years more before investigators got a big break in the case, these officials said. Sometime in mid-2010, the man was overheard using a phone by intelligence officials, who then were able to locate his residence - the specially constructed $1 million compound with walls as high as 18 feet topped with barbed wire.

U.S. counterterrorism officials considered bombing the place, an option that was discarded by the White House as too risky, particularly if it turned out bin Laden was not there.

Instead, Obama signed an order on Friday for a team of SEALs to chopper onto the compound under the cover of darkness. In the ensuing 48 hours, the president toured tornado-damaged Alabama and delivered a joke-filled after-dinner speech to the White House Correspondents Association. When the operation got under way, though, he slid into his chair in the Situation Room in the White House, where Brennan said the president and his aides "were able to monitor in a real-time basis the progress of the operation" from beginning to end.

Brennan strongly suggested a live video feed was available - SEALs customarily have video cameras attached to their helmets - and the White House released a photo showing the commander in chief, Vice President Joe Biden and top aides staring intently at something outside the picture. The White House did not say what they were looking at.

According to officials who declined to be identified by name, bin Laden was shot in the head during a firefight, and his body was identified to near 100 percent certainty through DNA testing. Photo analysis by the CIA, confirmation by a woman believed to be one of bin Laden's wives, who was also at the compound, and matching physical features added confirmation, they said.

In addition to bin Laden, one of his sons, Khalid, was killed in the raid, as was the wife who shielded him, Brennan said. Also killed were two of bin Laden's al-Qaida facilitators, including the one who was apparently listed as the owner of the residence, Brennan said.

Some individuals found at the compound were left behind when the SEALs withdrew and were turned over to Pakistani authorities who quickly took over control of the site, officials said.

Within 40 minutes, the operation was over, and the SEALs flew out - minus one helicopter, which had malfunctioned and had to be destroyed. Bin Laden's remains were flown to the USS Carl Vinson, then lowered into the North Arabian Sea.

There was one last nerve-wracking moment back inside the White House, Brennan said, when the Pakistanis started scrambling their jets and there was brief concern that the U.S. force might be in danger.

The decision to bury the body at sea drew condemnation from some Muslim clerics despite Obama's statement that the burial was handled in accordance with Islamic tradition.

"They can say they buried him at sea, but they cannot say they did it according to Islam," said Mohammed al-Qubaisi, Dubai's grand mufti. "Sea burials are permissible for Muslims in extraordinary circumstances. This is not one of them."

As quickly as bin Laden's supporters vowed to avenge his death, administration officials worked to undermine his reputation.

"Here is bin Laden, who has been calling for these (terror) attacks, living in this million-dollar-plus compound, living in an area that is far removed from the front, hiding behind women who were put in front of him as a shield. I think it really just speaks to just how false his narrative has been over the years," said Brennan.

Bin Laden's death came 15 years after he declared war on the United States. Al-Qaida was also blamed for the 1998 bombings of two U.S. embassies in Africa that killed 224 people and the 2000 attack on the USS Cole that killed 17 American sailors in Yemen, as well as countless other plots, some successful and some foiled.

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