In March, Obama authorized the development of a plan for the United States to bomb bin Laden's compound with two B2 stealth bombers dropping a few dozen 2,000-pound bombs, sources tell ABC News. But when the president heard the compound would be reduced to rubble, he changed his mind because it would mean there would be no evidence to present to the world that the head founder and leader of al Qaeda was indeed dead. Plus, all 22 people in the compound including women and children and likely many neighbors would also be killed.
So he instead authorized this risky operation, scheduled for a time of little moonlight, so U.S. helicopters could enter into Pakistan low to the ground and undetected.
The operation was authorized Friday morning and was originally planned for Saturday night, but on Friday, for weather reasons, it was pushed to Sunday.
Four helicopters swooped in to the compound and the Navy Seals fought a close quarters gunbattle. They ordered bin Laden to surrender, but the 54-year-old who had vowed he would not be caught alive, refused. He was then shot dead. His son, Khalid, was also killed in the raid.
Bin Laden's death was marked by jubilance, as crowds gathered at Ground Zero in New York and outside the White House chanting "USA, USA."
Congratulations poured in, with even former vice president Dick Cheney, a leading critic of the Obama administration, congratulating the president.
"Today, the message our forces have sent is clear -- if you attack the United States, we will find you and bring you to justice," Cheney said in a statement.
Bin Laden's death also prompted security alerts in the United States.
In New York City, Police Commissioner Raymond Kelly ordered the shift that was to go off duty at midnight be held over this morning to increase police presence in the subway system during this morning's rush hours. He also ordered that all members of the NYPD remain alert in the aftermath of the announcement of bin Laden has been killed.
Security was stepped up at the site of the 9/11 attack and in New York subways.
Washington police were also put on heightened alert and officials said there would be a show of force, especially near transit hubs, hotels and government buildings.
Philadelphia's Police Commissioner Charles Ramsey instructed dispatchers to ensure there are hourly checks on all mosques and synagogues in the city and police were put a heightened alert until further notice.
U.S. embassies have been put on high alert since the news was revealed, and the Department of Homeland Security and the FBI are reminding security forces around the country to be vigilant for suspicious activity amid concerns about possible retaliation.