WATCH LIVE: NYC holds 9/11 memorial service on 15th anniversary

New York City is set to hold a memorial service on Sunday morning, the 15th anniversary of 9/11.

The coordinated attacks on September 11, 2001 took the lives of 2,996 innocent people, making it the deadliest attack on American soil in history. More than 6,000 other were injured.

Nineteen terrorists hijacked 4 jetliners in the early hours. Two of the plans hit the World Trade Center towers, one stuck the Pentagon building in Washington, D.C. and one crashed in a field in Shanksville, Pennsylvania.

15 most iconic images from September 11, 2001 and aftermath

During New York City's memorial service, the first bells will ring at Ground Zero at 8:46 a.m. ET to commemorate Flight 11 hitting the North Tower. Bells will ring again at 9:03 a.m. ET to commemorate Flight 175 hitting the South Tower. At 10:28 a.m. ET bells are scheduled to ring to commemorate the North Tower collapsing.

Names of all the victims will be read aloud at the solemn service in lower Manhattan.

Photos of 9/11 memorials at the Pentagon, in Shanksville, Penn., and elsewhere