Buildingagain The north side of the Albert P. Murrah Federal Building in Oklahoma City shows 19 April 1995 the devastation caused by a fuel-and fertilizer truck bomb that was detonated early 19 April in front of the building. The blast, the worst terror attack on US soil, killed 168 people and injured more than 500. Timothy McVeigh, convicted on first-degree murder charges for the 19 April bombing was sentenced to death in 1997. AFP PHOTO BOB DAEMMRICH (Photo credit should read BOB DAEMMRICH/AFP via Getty Images) (AFP)
Man2 Bureau of Arms, Tobacco and Firearms (ATF) agent Luke Franey (L) hugs Oklahoma city ATF Bureau manager Valerie Rauden (R) in front of the remains of the Alfred P. Murrah building in downtown Oklahoma city 05 May during a memorial service in memory of the victims of the 19 April car-bombing. Rauden and Franey were inside the building at the time of the bombing. Authorities say that 165 people died as a consequence of the bombing. AFP PHOTO (Photo credit should read ROBERTO SCHMIDT/AFP via Getty Images) (AFP)
Murraughbuilding1 N220195 02: FILE PHOTO: Protective covering drapes over the Alfred P. Murrah Federal Building in Oklahoma City, April 19, 1995 where a terrorist bomb killed 168 people. On the fifth anniversary of the bombing, survivors, victims'' family members, friends and rescue personnel gathered at the bombing site April 19, 2000 to officially dedicate a national park built to honor the people killed in the 1995 bombing. (Photo by J. Pat Carter/Liaison) (J. Pat Carter)
Wreckage2 This picture released by FEMA 22 April shows Los Angeles County fireman surveying the wreckage of the federal building in Oklahoma City, Oklahoma 21 April in attempt to find clues or remaining survivors after the bombing. Seventy-eight people are confirmed dead and over 150 are still missing. AFP PHOTO (Photo credit should read FEMA POOL/AFP via Getty Images) (AFP)
Photos: 25th anniversary of Oklahoma City bombing Rescue crews and agents from several federal agencies stand in front of the remains of the Alfred P. Murrah building in downtown Oklahoma City 05 May during a memorial service in memory of the victims who died in the 19 April car-bombing. Authorities say that 165 people died as a consequence of the bombing and that two others remain missing. AFP PHOTO (Photo credit should read ROBERTO SCHMIDT/AFP via Getty Images) (AFP)
Photos: 25th anniversary of Oklahoma City bombing This picture released by FEMA 22 April shows Los Angeles County fireman surveying the wreckage of the federal building in Oklahoma City, Oklahoma 21 April in attempt to find clues or remaining survivors after the bombing. Seventy-eight people are confirmed dead and over 150 are still missing. AFP PHOTO (Photo credit should read FEMA POOL/AFP via Getty Images) (AFP)
People2 N220195 04: Frightened civilians react to the terrorist bombing at the Alfred P. Murrah Federal Building in Oklahoma City, April 19, 1995 killing 168 people. (photo by J. Pat Carter) (J. Pat Carter)
Bear OKLAHOMA CITY, UNITED STATES: Tina Babcock of Oklahoma City holds a teddy bear as she attends a candlelight memorial service 17 April held at the Parents Assistance Center to remember the 19 children killed in the Oklahoma City bombing. The teddy bear has become the symbol for children killed in the 19 April 1995 bombing of the Alfred P. Murrah Federal Building. AFP PHOTO/Chris WILKINS (Photo credit should read CHRIS WILKINS/AFP via Getty Images) (CHRIS WILKINS)
Photos: 25th anniversary of Oklahoma City bombing (Original Caption) Aftermath of the bombing of the Alfred P. Murrah Federal Building. (Photo by �� Greg Smith/CORBIS/Corbis via Getty Images) (Gregory Smith)
Victims3 Family members of those lost in the Oklahoma City bombing grieve as they watch the remains of the Alfred P. Murrah building be demolished. On April 19, 1995, Timothy McVeigh exploded a truck bomb outside of the Alfred P. Murrah Federal Building, killing 168 people and injuring more than 500 in what was at the time the largest terror attack on American soil. (Photo by David Butow/Corbis via Getty Images) (David Butow)
Newspaper DENVER, CO - JUNE 13: Wendy Heiser (L) and Dee Weiland read an extra edition of the Rocky Mountain News in front of the Byron G. Rogers Federal Building and United States Court House in Denver, Colorado moments after hearing Timothy McVeigh had received the death sentence13 June. A jury convicted McVeigh 02 June on 11 counts of murder and conspiracy stemming from the 19 April, 1995 Oklahoma City bombing. (Photo credit should read DOUG COLLIER/AFP via Getty Images) (DOUG COLLIER)
Photos: 25th anniversary of Oklahoma City bombing Mike Traynor,the uncle of Ashley Eckles, hugs a police officer after attending a 24 April burial service at the Summit View Cemetery in Guthrie, Oklahoma, for four-year-old Ashley . The child was killed in the 19 April car-bombing of the Alfred P. Murrah Federal Building in Oklahoma City. AFP PHOTO
(Photo credit should read TIMOTHY A. CLARY/AFP via Getty Images) (TIMOTHY A. CLARY)
Photos: 25th anniversary of Oklahoma City bombing Rescue workers search through the rubble 29 April in the Federal Building in Oklahoma City looking for any survivors from the 19 April bombing. Work was halted during 29 April because of falling debris that was a danger to the rescuers. AFP PHOTO (Photo credit should read Roman BAS/AFP via Getty Images) (AFP)
Photos: 25th anniversary of Oklahoma City bombing A rescue crew searches for bodies 20 April in the Alfred P. Murrah Federal building in Oklahoma City. The death toll in the 19 April car bombing has risen to 52. AFP PHOTO (Photo credit should read POOL/AFP via Getty Images) (AFP)
Photos: 25th anniversary of Oklahoma City bombing Oklahoma City terrorist bombing victim Brandon Denny,4, lying in hospital bed as parents Jim & Claudia hold up his birthday cupcake lit up w. 2 candles at Presbyterian Hospital. (Photo by Taro Yamasaki/The LIFE Images Collection via Getty Images/Getty Images) (Taro Yamasaki)
McVeigh1 PERRY, OK - APRIL 21: This 21 April 1995 file photo shows Timothy McVeigh (C) being led from the Noble County Courthouse in Perry, Oklahoma, by FBI agents after being charged with involvement in the 19 April 1995 bombing of the Alfred P. Murrah Federal Building in Oklahoma City, Oklahoma. McVeigh, who was convicted of the bombing that killed 168 people, is scheduled to be executed in Terre Haute, IN, 11 June, 2001. (Photo credit should read BOB DAEMMERICH/AFP via Getty Images) (BOB DAEMMRICH)
McVeigh 227868 01: Alleged Oklahoma City bomber Timothy McVeigh sits for an interview with Rob Night (left) and Stephen Jones while in prison June 23, 1995 in Oklahoma City, OK. The government believes that Timothy McVeigh took it upon himself to avenge the Waco tragedy by bombing the Oklahoma City federal building exactly two years later. (Photo by Pool/Liaison) (Pool)
Nicholsmug Terry Nichols was convicted of being an accomplice to Timothy McVeigh in the Oklahoma City bombing of the Alfred P. Murrah Federal Building in April 1995. (Photo by Bureau of Prisons/Getty Images) (Donaldson Collection)
Memorial3 Visitors to the Oklahoma City National Memorial walk among empty chairs that signify those lost in the Oklahoma City bombing. On April 19, 1995, Timothy McVeigh exploded a truck bomb outside of the Alfred P. Murrah Federal Building, killing 168 people and injuring more than 500 in what was at the time the largest terror attack on American soil. (Photo by David Butow/Corbis via Getty Images) (David Butow)
Photos: 25th anniversary of Oklahoma City bombing Oklahoma City Natl. Memorial field of chairs, 168 bronze-dipped empty chairs commemorating victims of 1995 terrorist bombing of Murrah Federal bldg. (Photo by Steve Liss/The LIFE Images Collection via Getty Images/Getty Images) (Steve Liss)
Photos: 25th anniversary of Oklahoma City bombing OKLAHOMA CITY, UNITED STATES: Greg Leasure prays in front of the chair representing his killed sister in the Field of Empty Chairs sector of the Oklahoma City National Memorial in downtown Oklahoma City 11 June 2001. The memorial was built to honor each of the 168 victims who died when the Alfred P. Murrah federal building was destroyed by a truck bomb on 19 April, 1995 at 9:02 am. Timothy McVeigh who authorities prosecuted and later found guilty of carrying out the bombing was executed 11 June in a federal prison in Terre Haute, Indiana. AFP PHOTO/ ROBERTO SCHMIDT (Photo credit should read ROBERTO SCHMIDT/AFP via Getty Images) (ROBERTO SCHMIDT)
Photos: 25th anniversary of Oklahoma City bombing OKLAHOMA CITY, OK - APRIL 25: Los Angeles Firefighters Greg Gonzalez(L) and Tracie Gallagher(R) rest with their dogs 24 April at the site of the 19 April bomb attack on the Oklahoma federal building, as rescue efforts to find any survivors continue. The official death toll in the attack rose to 79, authorities said 24 April. AFP PHOTO (Photo credit should read POO/AFP via Getty Images) (POOL)
Photos: 25th anniversary of Oklahoma City bombing OKLAHOMA CITY, UNITED STATES: US President Bill Clinton (L) and Doris Jones, who lost a family member in the Oklahom City bombing, visit the victims National Memorial 19 April, 2000, in Oaklahoma City. The memorial was dedicated 19 April, the fifth anniversary of the bombing of the Alfred P. Murrah Federal Building where 168 people died. (ELECTRONIC IMAGE) AFP PHOTO/Luke FRAZZA (Photo credit should read LUKE FRAZZA/AFP via Getty Images) (LUKE FRAZZA)
Photos: 25th anniversary of Oklahoma City bombing Jimmy Boldien hugs the chair of his dead aunt Laura Jane Garrison in the Field of Empty Chairs sector of the Oklahoma City National Memorial in downtown Oklahoma City 11 June 2001. The memorial was built to honor each of the 168 victims who died when the Alfred P. Murrah federal building was destroyed by a truck bomb on 19 April, 1995 at 9:02 am. Timothy McVeigh, who authorities prosecuted and later found guilty of carrying out the bombing, was executed 11 June in a federal prison in Terre Haute, Indiana. AFP PHOTO/ROBERTO SCHMIDT (Photo credit should read ROBERTO SCHMIDT/AFP via Getty Images) (ROBERTO SCHMIDT)
Photos: 25th anniversary of Oklahoma City bombing OKLAHOMA CITY, OK - APRIL 19: Jay B. Walker visits his fraternity brother for the first time before the memorial service as Oklahoma City marks the 21st anniversary of the terrorist bombing on April 19, 2016 in Oklahoma City, Oklahoma. Timothy McVeigh and Terry Nichols carried out the bombing in 1995 of the Alfred P. Murrah Federal Building that killed 169 people and injured more than 680 others. There is a memorial chair hand-crafted from glass, bronze, and stone for each victim of the bombing. (Photo by J Pat Carter/Getty Images) (J Pat Carter)
Photos: 25th anniversary of Oklahoma City bombing Visitors to the Oklahoma City National Memorial walk among empty chairs that signify those lost in the Oklahoma City bombing. On April 19, 1995, Timothy McVeigh exploded a truck bomb outside of the Alfred P. Murrah Federal Building, killing 168 people and injuring more than 500 in what was at the time the largest terror attack on American soil. (Photo by David Butow/Corbis via Getty Images) (David Butow)