Al Qaeda leader Osama bin Laden was killed Sunday in a firefight with U.S. forces in Pakistan and his body was recovered, President Barack Obama said on Sunday. "Justice has been done," Obama said in a dramatic, late-night White House speech announcing the death of the elusive mastermind of the September 11 , 2001 , attacks on New York and Washington that killed nearly 3 ,000 people. It is was major accomplishment for Obama and his national security team and could give him a political boost as he seeks re-election in 2012. And it was at least a huge symbolic blow to al Qaeda, the militant organization that has staged bloody attacks in many western and Arab countries cities and has been the subject of a worldwide campaign against it. Obama said U.S. forces led a targeted operation that killed bin Laden in Abbotabad north of Islamabad. No Americans were killed in the operation and they took care to avoid civilian casualties, he said. In Washington, thousands of people gathered quickly outside the White House, waving American flags, cheering and chanting "USA, USA, USA." Car drivers blew their horns in celebration and people streamed to Lafayette Park across from the presidential mansion. Police vehicles with their lights flashing stood vigil. "I'm down here to witness the history. My boyfriend is commissioning as a Marine next week. So I'm really proud of the troops," Laura Vogler, a junior at American University in Washington, said outside the White House. Many Americans had given up hope of ever finding bin Laden after he vanished in the mountains of eastern Afghanistan in late 2001 as U.S. and allied forces invaded the country in response to the September 11 attacks. Intelligence that originated last August provided the clues that eventually led to bin Laden's trail, the president said. A U.S. official said Obama gave the final order to pursue the operation last Friday morning. "The United States has conducted an operation that killed Osama bin Laden, the leader of al Qaeda and a terrorist who is responsible for the murder of thousands of men, women and children," Obama said. A crowd gathered in Lafayette Park outside the White House erupted in jubilation at the news. Hundreds of people waved flags, hugged and cheered. CAPTURED DEAD Former President George W. Bush, who famously vowed to bring bin Laden to justice "dead or alive" but never did, called the operation a " momentous achievement" after Obama called him with the news. Martin Indyk, a former U.S. assistant secretary of state for near eastern affairs, described bin Laden's death as "a body blow" to al Qaeda at a time when its ideology was already being undercut by the popular revolutions in the Arab world. Statements of appreciation poured in from both sides of Washington's often divided political divide. Republican Senator John McCain declared, "I am overjoyed that we finally got the world's top terrorist. " Said former President Bill Clinton: " I congratulate the president, the national security team and the members of our armed forces on bringing Osama bin Laden to justice after more than a decade of murderous al Qaeda attacks." Having the body may help convince any doubters that bin Laden is really dead. Bin Laden had been hunted since he eluded U.S. soldiers and Afghan militia forces in a large-scale assault on the Tora Bora mountains of Afghanistan close to the Pakistan frontier in 2001. The trail quickly went cold after he disappeared and many intelligence officials believed he had been hiding in Pakistan. While in hiding, bin Laden had taunted the West and advocated his militant Islamist views in videotapes spirited from his hideaway. Besides September 11 , Washington has also linked bin Laden to a string of attacks -- including the 1998 bombings of American embassies in Kenya and Tanzania and the 2000 bombing of the warship USS Cole in Yemen .