Close Call on the Arctic's Melting Sea Ice

Tracking Elusive Narwhals in the Arctic

Part 1: These creatures known as the "unicorns of the sea" are threatened by climate change.

Part 2: A desperate scramble over a massive crack in the sea ice creates a scary situation.

Climate Change Threatens Arctic Life

Part 3: Warming global temperatures are melting critical sea ice.

Proof of Heaven?

Meet a brain surgeon whose near-death experience convinced him heaven was real.

'Christmas Story' Takes Broadway: Where Is Ralphie Now?

ABC's Neal Karlinsky caught up with child actor turned Emmy-nominated producer Peter Billingsley.

Britain's Beloved Christmas Pudding

ABC's Nick Watt unravels the mystery of his homeland's most loved fruit cake.

NRA Faces Backlash for Proposing Armed School Guards

Protestors crashed the NRA's first news conference since the Newtown, Conn., school massacre.

Bloomberg Thorws Punch at NRA, Obama

Bloomberg says NRA "encourages behavior that causes things like Connecticut" shooting.

Gun Violence Victims, Survivors Share Thoughts After Newtown Massacre

From Aurora to Virginia Tech, victims of mass shootings explain how their lives were changed.

A Day in the Life of the American Gun

Part 1: "Nightline" goes across the country to embed with police and trauma rooms.

For Utah Family, Guns Are a Revered Family Tradition

Part 2: The Laveres taught their two young children how to shoot at an early age.

Guns in America: Searching for Solutions

Part 3: Police officers, doctors and gunshot victims offer their thoughts on the future of gun control.

Transcript for Close Call on the Arctic's Melting Sea Ice