3. Oklahoma City (Bomb in Oklahoma)

One April morning in 1995, at Oklahoma City's Alfred P. Murrah Federal Building, Timothy McVeigh parks a truck packed with explosives at the front of the government landmark. At 9:02AM, it explodes and the front of the building collapses with a loss of 168 lives. Survivors recount the terrifying experience as investigators attempt to discover what caused the building to collapse.