US is marking the 15th anniversary of the 9/11 terror attack

The United States is marking the 15th anniversary of the 9/11 terror attacks with solemn services to commemorate the victims of the deadliest terror attacks.

On September 11, 2001, a day of grief, when four passenger jets were hijacked by Islamic extremist group Al-Qaeda and crashed them into the Twin Towers in New York City, the Pentagon in Washington, D.C. and a field in Shanksville, Pennsylvania killing nearly 3,000 people.

Two of the planes hit the twin towers of World Trade Center in New York City, one plane hit the Pentagon outside Washington, D.C., and the other plane crashed in a field in Pennsylvania.

The attacks resulted in extensive death and destruction.

“September 11, 2001, touched every single one of us,” New York City Mayor Bill de Blasio said Saturday during a memorial service at St. Patrick’s Cathedral.

“There is no New Yorker who somehow evaded the pain of that day. We all felt it. We all were affected. Everyone felt it. Everyone suffered.”

The nearly 3,000 people who died in the attacks are being remembered this weekend with parades and memorials.

“This weekend, we honour their memory once more. We stand with the survivors who still bear the scars of that day,” Mr Obama said on Saturday.

There will be special services at the spots where the planes crashed. The service will pause six times to mark the moments when each of the two planes hit the Twin Towers, when each tower fell, the attack on the Pentagon and a crashed in Pennsylvania.