'Avengers': Superhero-Packed Film

Oklahoma Tornado: Stories of Survival and Hope

Families reunited after a monster tornado leveled Moore, Okla., killing at least 24 people.

Oklahoma Tornado: Search and Recovery

How neighbors in Moore, Okla., made it through the worst case scenario

Oklahoma Tornado: Shocking Images After the Storm

Photographers captured now iconic images of rescues and devastation.

Massive Tornado Devastates Oklahoma City Area, Dozens Killed

Elementary schools, homes and hospitals were destroyed in the monster twister's wake.

Tornado Outbreak: Destruction in the Heartland

The Midwest has suffered from three straight days of tornado activity.

Oklahoma Tornado: Search and Recovery

Oklahoma Lt. Gov. Todd Lamb gives "Nightline" the latest on rescue efforts in Moore, Okla.

Powerball Madness: More Than $600M Up for Grabs

Lotto fever sweeps the nation as one of the biggest jackpots in history approaches.

Ethan Hawke, Julie Delpy on 'Before Midnight'

Stars open up about their on-screen chemistry and off-screen heartache.

Two Brothers Tackle Alaskan Wilderness

Contestants on Nat Geo's "Ultimate Survival: Alaska" have to survive alone for days.

Powerball Madness: More Than $600M Up for Grabs

Lotto fever sweeps the nation as one of the biggest jackpots in history approaches.

Lone Survivor of 1987 Plane Crash Breaks Silence

In the documentary "Sole Survivor," Cecelia Crocker talks about living with survivor's guilt.

Demi Lovato: 'Warrior' For Life

Pop star talks about how fame can mean pain, and what she would say to Lindsay Lohan.