Helicopters descended out of darkness on the most important counter-terrorism mission in US history. It was an operation so secret, only a select few US officials knew what was about to happen.
The location was a fortified compound in the Pakistani town of Abbottabad. The target was Osama bin Laden.
Intelligence officials discovered the compound in August while monitoring an al Qaeda courier.
The CIA had been hunting that courier for years, ever since detainees told interrogators that the courier was so trusted by bin Laden that he might very well be living with the al Qaeda leader.
Nestled in an affluent neighborhood, the compound was surrounded by high walls and two security gates guarded the only way in. No phone lines or internet cables ran to the property.
By mid-February, intelligence from multiple sources was clear enough that Obama wanted to "pursue an aggressive course of action," a senior administration official said.
On April 29, Obama approved an operation to kill bin Laden. It was a mission that required surgical accuracy, even more precision than could be delivered by the US government's sophisticated Predator drones.
To execute it, Obama tapped a small contingent of the Navy's elite Seal Team Six and put them under the command of CIA director Leon Panetta, whose analysts monitored the compound from afar.
Details of exactly how the raid unfolded remain murky.
But the al Qaeda courier, his brother and one of bin Laden's sons were killed. No American was injured.