The United States is now certain that Osama Bin Laden is dead. Nearly ten years to the anniversary of the 9/11 attacks.

Obama will announce Osama bin Laden has been killed almost a decade after the terrorist attacks on 9/11, CNN and the New York Times reported. *developing*

Osama bin Laden, hunted as the mastermind behind the worst-ever terrorist attack on U.S. soil, has been killed, sources told ABC News.

His death brings to an end a tumultuous life that saw bin Laden go from being the carefree son of a Saudi billionaire, to terrorist leader and the most wanted man in the world.

Bin Laden created and funded the al Qaeda terror network, which was responsible for the Sept. 11, 2001, attacks on the United States. The Saudi exile had been a man on the run since the U.S.-led invasion of Afghanistan overthrew the ruling Taliban regime, which harbored bin Laden.

Osama bin Laden Killed - ID Confirmed by DNA Testing

Osama bin Laden, hunted as the mastermind behind the worst-ever terrorist attack on U.S. soil, has been killed, President Obama announced tonight.

Bin Laden was located at a compound in Pakistan, which was monitored and when the time was determined to be right, U.S. forces struck, the president said.

"A small team of Americans carried out the operation," Obama said. "After a firefight, they killed Osama bin Laden and took custody of his body."

DNA testing confirmed that it was bin Laden, sources told ABC News.

Sources said the attack was carried out by Joint Special Operations Command forces working with the CIA.

Vice President Biden briefed Republican congressional leaders this evening on the operation, which had been kept secret until shortly before the president's announcement tonight.

"This is a terrific day for America and quite frankly the whole world that cares about winning the war on terror," former Bush chief of staff Andy Card told ABC News. Card said the news is "particularly significant" for the intelligence community.

"They're the ones who kept their nose to the grindstone and worked very hard to allow this day to be realized ... finally," he said.

His death brings to an end a tumultuous life that saw bin Laden go from being the carefree son of a Saudi billionaire, to terrorist leader and the most wanted man in the world.

Bin Laden created and funded the al Qaeda terror network, which was responsible for the Sept. 11, 2001, attacks on the United States. The Saudi exile had been a man on the run since the U.S.-led invasion of Afghanistan overthrew the ruling Taliban regime, which harbored bin Laden.