Watch the special expanded series finale online now.
Astrophysicist Neil deGrasse Tyson, director of the Hayden Planetarium, speaks to NBC's Lester Holt about the meteor and asteroid that approached Earth on Friday. (Nightly News)
Tampa police Chief Jane Castor says Jared Cano, a 17-year-old expelled student, had threatened to plant a device at Freedom High School. Watch her statement. (NBC News)
Congressional hearings reveal a long history of problems at Arlington National Cemetery, including a possible 6,600 flawed burials. NBC's Leanne Gregg reports.