OKLAHOMA CITY — Survivors and family members of the 168 people who died in the bombing of the Oklahoma City federal building gathered today to commemorate the 15th anniversary of the attack.

Hundreds of people attended the ceremony at the Oklahoma City National Memorial to remember those killed in the April 19, 1995, explosion. More than 600 others were injured in the attack at the Alfred P. Murrah Federal Building.

Before the ceremony, bells tolled in Oklahoma City's downtown and some family members visited the site of the federal building razed in the attack, where chairs to honor the bombing victims now stand.

Attending the ceremony was Charlie Hangar, the Oklahoma Highway Patrol trooper who stopped bomber Timothy McVeigh on Interstate 35 the day of the bombing because his 1977 Mercury Marquis did not have a license plate. He is now the Noble County sheriff.

McVeigh was convicted on federal murder charges and executed in 2001. His Army buddy, Terry Nichols, was convicted on federal and state bombing-related charges and is serving multiple life sentences at a federal prison in Colorado.

By The Associated Press