CRIME

AP PHOTOS: Images of Oklahoma City bombing of federal building ahead of 20th anniversary

  • FILE - In this April 19, 1995 file photo, rescue personnel converge on the bombed Alfred Murrah Federal Building in Oklahoma City. The blast killed 168 people _ including 19 children _ injured hundreds more and caused hundreds of millions of dollars in damage to structures and vehicles in the downtown area. (AP Photo/Rick Bowmer, File)

    FILE - In this April 19, 1995 file photo, rescue personnel converge on the bombed Alfred Murrah Federal Building in Oklahoma City. The blast killed 168 people _ including 19 children _ injured hundreds more and caused hundreds of millions of dollars in damage to structures and vehicles in the downtown area. (AP Photo/Rick Bowmer, File)  (The Associated Press)

  • FILE - In this April 19, 1995 file photo, people injured in the car bomb blast at the Alfred P. Murrah Federal Building in downtown Oklahoma City gather near the explosion site. The blast killed 168 people _ including 19 children _ injured hundreds more and caused hundreds of millions of dollars in damage to structures and vehicles in the downtown area. (AP Photo/David Longstreath)

    FILE - In this April 19, 1995 file photo, people injured in the car bomb blast at the Alfred P. Murrah Federal Building in downtown Oklahoma City gather near the explosion site. The blast killed 168 people _ including 19 children _ injured hundreds more and caused hundreds of millions of dollars in damage to structures and vehicles in the downtown area. (AP Photo/David Longstreath)  (The Associated Press)

  • FILE - In this April 19, 1995 file photo, medical assistants, Janet Froehlich, left, Wilma Jackson and Kerri Albright run from the Alfred Murrah Federal Building after being told another bomb device had been found in Oklahoma City. The blast killed 168 people _ including 19 children _ injured hundreds more and caused hundreds of millions of dollars in damage to structures and vehicles in the downtown area. (AP Photo/David J. Phillip)

    FILE - In this April 19, 1995 file photo, medical assistants, Janet Froehlich, left, Wilma Jackson and Kerri Albright run from the Alfred Murrah Federal Building after being told another bomb device had been found in Oklahoma City. The blast killed 168 people _ including 19 children _ injured hundreds more and caused hundreds of millions of dollars in damage to structures and vehicles in the downtown area. (AP Photo/David J. Phillip)  (The Associated Press)

A cargo truck laden with more than two tons of explosives was detonated in front of Oklahoma City's nine-story federal building on April 19, 1995 — an act of terrorism that at the time was the worst such attack ever committed on U.S. soil.

The blast killed 168 people, including 19 children, injured hundreds more and caused hundreds of millions of dollars in damage to structures and vehicles in the downtown area.

President Bill Clinton led a memorial service for the victims as the FBI launched a nationwide investigation to find those responsible.

Within days, Timothy McVeigh and Terry Nichols were arrested and accused of conspiring to destroy the federal building in retribution for the government's handling of the siege of the Branch Davidian religious group at their compound in Waco, Texas, two years earlier.

McVeigh and Nichols were tried and convicted on federal charges, and Nichols was convicted of murder following a separate trial in Oklahoma. McVeigh was sentenced to death and executed and Nichols received multiple life prison sentences.

A memorial to the bombing's victims now sits on the former site of the federal building, and a nearby building that was damaged in the bombing houses an interactive museum.

Each year on the bombing's anniversary, family members of victims, survivors, rescue workers and others return to the memorial for a remembrance ceremony.