Oklahoma City Bombing

Rescue workers stand in front of the Alfred P. Murrah Federal Building following an explosion, April 19, 1995, in downtown Oklahoma City.

Oklahoma City District Fire Chief Mike Shannon searches through the rubble of the Alfred P. Murrah Federal Building moments after the explosion, April 19, 1995, in downtown Oklahoma City. Shannon was one of the first to arrive on scene following the domestic terror attack.

Two women wait to be rescued from the upper floors of the Alfred Murrah Federal Building, April 19, 1995.

An unidentified woman calls out to friends as she waits for treatment following the bombing at the Alfred P. Murrah Federal Building in downtown Oklahoma City, April 19, 1995.

An unidentified woman comforts an injured child following the explosion at the Alfred Murrah Federal Building in downtown Oklahoma City, April 19, 1995.

People injured in the blast at the Alfred P. Murrah Federal Building in downtown Oklahoma City gather near the explosion site, April 19, 1995.

Licensed practical nurse Rebecca Anderson of Midwest City, Okla., a volunteer, receives emergency care after being struck by debris. Four days later Anderson died - the only member of the Oklahoma City rescue team to die.

Family members wait for word on relatives missing after the bombing, at First Christian Church in Oklahoma City, April 19, 1995. The church was used as the briefing center for family members.

An unidentified man looks at the bomb-damaged Alfred Murrah Federal Building, April 19, 1995.

An unidentified man holds a towel to his face following the bombing at the Alfred Murrah Federal Building in downtown Oklahoma City, April 19, 1995.

Carlos DeLarosa cleans up around an upholstery store near the Alfred P. Murrah Federal Building, April 19, 1995, in Oklahoma City. The business was destroyed in the explosion in front of the federal office building.

An unidentified man stands in the blown-out doorway of a business just a few blocks away from the Alfred P. Murrah Federal Building, April 19, 1995.

The gaping hole in the front of the Alfred Murrah Federal Building is seen from the sky, April 20, 1995, in Oklahoma City.

The downtown streets surrounding the Alfred Murrah Federal Building are swamped by emergency vehicles and personnel, April 20, 1995.

A firefighter moves a water hose near the Alfred Murrah Federal Building following the explosion, April 19, 1995.

Workers from the Oklahoma State Medical Examiners Office move a body bag on a gurney, April 20, 1995, in Oklahoma City.

Rescue workers search the Alfred P. Murrah Federal Building in Oklahoma City, April 24, 1995.

A message to the Oklahoma City Fire Department is seen sprayed on a makeshift hut at the bombing cleanup site in downtown Oklahoma City, April 28, 1995, as city firefighters take a break.

Offices of the nearby Liberty Bank building are lit to form a cross, April 21, 1995.