On April 19, 1995, a truck bomb exploded at the Alfred P. Murrah Federal Building in downtown Oklahoma City, killing 168 people -- 19 of them children in a day care center -- and forever changed the city and its residents. This year, the Oklahoma City National Memorial and Museum will hold a virtual remembrance ceremony to mark the 25th anniversary. KGOU will broadcast the ceremony at 9 a.m. on Sunday, April 19.