TONIGHT'S MUST-SEE

"P.O.V.: Libby, Montana," 10 p.m., PBS. Tucked into the northwest corner of the state, Libby, Mont., has immense beauty. People climb the Rocky Mountains and fish the clear Kootenai River. It also has volcanic deposits that provided 80 percent of the world's vermiculite. That was transformed into a multi-use material called Zonolite. Strip-mining it produced clouds of dust; workers began to die. Prosecutors now charge that the W.R. Grace Co. knew of the dangers for 30 years, without telling workers. Now comes the job of cleaning houses, schools and playgrounds. This film is a jolting story of a conservative town that once distrusted big government and now needs it.

"Live From New York: The First 5 Years of Saturday Night Live," 7 p.m., NBC. This is the best of the "SNL" films because of its frankness. It views the wondrous point when comic genius and crazed behavior co-existed.

OF NOTE

"The Aviator" (2004), 5 and 8 p.m., FX. Some critics have raved about Martin Scorsese's film about Howard Hughes (Leonardo DiCaprio). It won Oscars for its sets, costumes and more, including Cate Blanchett as Katharine Hepburn. We'll offer the minority view that the film obsessed on Hughes' quirks without finding his charm; also, this was a stylized, exaggerated Hepburn.

"Princess Diana: The Legend and Legacy of a Princess," 7 p.m., MyNetwork (KFVE). We might have more confidence in this special if it weren't followed by one ("The Spirit of Princess Diana") that consults psychics.

"Bones," 7 p.m., Fox. In this rerun, serial killer Howard Epps has escaped from his cell.

"Nova: The Storm That Drowned a City," 8 p.m., PBS. This reruns the documentary that viewed the Hurricane Katrina predictions and the obstacles to rebuilding New Orleans.

"House," 8 p.m., Fox. A teenager has a confused body. It thinks it has an infection but apparently doesn't.

"Law & Order: Special Victims Unit," 9 p.m., NBC. In a strong episode, Benson is contacted by her half-brother. Unfortunately, he's on the run from the law. There are key supporting roles for Kim Delaney as a cop and Vincent Spano as an FBI agent.

"NCIS," 9 p.m., CBS. John Billingsley plays a blind photographer who helps track a killer.