Thousands of people poured into the streets outside the White House and in New York City waving US flags, cheering and honking horns to celebrate al-Qaeda leader Osama bin Laden's death.

Almost 10 years after the 11 September, attacks on New York and Washington that killed nearly 3,000 people, residents found joy, comfort and closure with the death of the mastermind of the plot.

For many, it was a historic, long-overdue moment.

‘I never figured I'd be excited about someone's death. It's been a long time coming,’ firefighter Michael Carroll, 27, whose firefighter father died in the 9/11 attacks, said in New York.

‘It's finally here. ... it feels good.’

At Ground Zero, site of the World Trade Center Twin Towers toppled by al-Qaeda militants flying hijacked planes, thousands sang the US national anthem, popped champagne, drank from beer bottles and threw rolls of toilet paper into the air.

Another big crowd gathered in New York's Times Square.

‘With all the gloom and doom around us, we all needed this. Evil has been ripped from the world,’ said Guy Madsen a salesman from Clifton, New Jersey, who drove to Lower Manhattan with his 14-year-old son.

Many in Times Square recalled the thousands of New Yorkers who perished on a clear September Tuesday almost a decade ago. Some people held pictures of loved ones who died.

In Washington, people gathered outside the White House soon after the first reports that bin Laden had been slain in Pakistan by US forces and even before President Obama announced the news.

The boisterous crowd swelled into the thousands and chanted ‘USA, USA, USA.’

‘We had to be there to celebrate with everybody else. I'm very happy with the outcome of today's news,’ said Stephen Kelley, a Gulf War veteran and former US Marine, who said he rushed to the White House after his wife told him the news.

College students, who were just children when the attacks took place, turned out in huge numbers, like Jennifer Raymond, 18, wrapped in a huge US flag outside the White House.

‘We were all in our dorm rooms and everyone's Facebook was blowing up,’ Raymond said. ‘It's like 'Oh my God, Osama bin Laden's dead.' Everyone in the dorm was screaming. Everyone decided to come to the White House.’

The celebration may well have been the biggest crowd to gather spontaneously outside the White House since Obama's election in November 2008.

In New York City, Mayor Michael Bloomberg said in a statement: ‘New Yorkers have waited nearly 10 years for this news. It is my hope that it will bring some closure and comfort to all those who lost loved ones on September 11, 2001.’

Firefighters hold a special place in New Yorkers' memories of 9/11, as hundreds died in the collapse of the Twin Towers while racing up flights of stairs to rescue trapped people on upper floors.

‘This is a tremendous moment, and hopefully it will bring us together, it doesn't matter if you're Muslim or Christian or whatever,’ said firefighter Patrice McLeod. ‘We'll never give up.’

Donna Marsh O'Connor, who lost her pregnant daughter in the 2001 attacks and is active in the group September 11th Families for Peaceful Tomorrows, watched events unfold on television.

‘Osama bin Laden is dead, and so is my daughter,’ she told Reuters. ‘His death didn't bring her back. We are not a family which celebrates death, no matter who it is.’