On Nov. 20, 1983, Lawrence endured fallout from the blasts of nuclear missiles that struck neighboring Kansas City. The area was scorched by firestorms, citizens were vaporized, and those lucky enough to survive suffered the slower effects of radiation poisoning. At least that is what was portrayed in an ABC television movie that became one of the most watched and most controversial events of the decade. To celebrate the 25th anniversary of “The Day After,” a screening takes place at 7 p.m. today at Liberty Hall, 644 Mass., followed by a cast and crew panel discussion. Returning to Lawrence are director Nicholas Meyer, producer Robert Papazian, actor Jeff East, local casting director Jack Wright and former mayor David Longhurst. Host of the event is Kyle Harvey, a researcher at Macquarie University in Sydney, Australia, who specializes in politics and film of the 1980s and is studying “The Day After” as part of a doctorate project.