More than 12 years after the horrifying 9/11 attacks, the National September 11 Memorial and Museum has opened its doors at Ground Zero.
Princes William and Harry cracked jokes with each other as they made multi-billion pound deals for charity on a City trading floor.
A man widowed in the September 11 attacks has returned to the top of the World Trade Center to honour the memory of the wife he lost there.
Video footage of the aftermath of the 9/11 terror attacks in New York which was filmed from space is to be broadcast in full on UK TV for the first time.
The footage, which shows a plume of smoke stretching from the site of the devastated World Trade Centre towers, was filmed from the International Space Station by astronaut Frank Culbertson.
Hours after the attack Mr Culberston discovered his friend Chic Burlingame was one of the pilots killed, when his plane was hijacked by terrorists.
It will be shown next week as part of Channel 4'S 'Live From Space' season, featuring a number of documentaries about astronauts and a two-and-a-half hour live broadcast from the ISS and Mission Control in Huston, Texas on Sunday March 16.
Boston Logan International Airport officials have apologised for holding a fire drill - complete with smoke and flames - on the 12th anniversary of the September 11 attacks.
The airport announced on their official Facebook page that they would be carrying out the drill today which drew widespread criticism on the social networking site.
One Facebook user wrote "how clueless and insensitive can you be", while another said "talk about out of touch."
Only two hours before the fire drill post, the Boston Logan International Airport's Facebook page said "Remembers" in relation to the attacks.
The Massachusetts Port Authority, who runs the airport, released a statement saying that it "apologises for conducting the fire training exercise and understands that it may have offended many of those touched by the events of September 11."
The two hijacked planes that hit the World Trade Center towers flew out of Logan airport.
President Barack Obama has attended a memorial service at the Pentagon to mark the 12th anniversary of the terror attacks. Along with prayers and speeches, a silence held to mark the moment American Airlines flight 77 crashed at the site, killing 184 people.
Relatives of those who died in the attack were among those who attended the service.
Relatives of those who died in the terror attacks of September 11, 2001, have retuned to the 9/11 Memorial to pay their respects on the 12th anniversary of the atrocities.
US President Barack Obama has led a moment of silence to mark the 12th anniversary of the 9/11 attacks.
Obama, along with the First Lady Michelle Obama, Vice President Joe Biden and his wife Jill, walked out of the White House at 1246 GMT - the moment the first hijacked plane hit the World Trade Center tower in New York:
President Barack Obama has led a moment of silence to remember those who died during the 9/11 terrorist attacks.
Secretary General of Nato, Anders Fogh Ramussen, has tweeted a photograph of the flags at half-mast at NATO headquarters in Brussels to mark the 9/11 anniversary.
In a second tweet, he added: "Deepest sympathy to people of all our countries who suffered from terrorism. NATO's commitment to fighting terrorism remains unwavering."
The US Ambassador to the UK, Matthew Barzun, has tweeted a photograph of a floral tribute sent to the American Embassy in London from David Cameron to mark the 12th anniversary of the 9/11 attacks.