Welcome to the "Nightline's" live blog, where the staff share interesting tidbits throughout the day.

7:23 p.m. ET: Move over, Lassie. A Massachusetts pit bull named Lilly took on a freight train last week to save her owner, who collapsed unconscious onto the tracks during a late-night walk in Shirley.

ABC's Sydney Lupkin reports The 8-year-old dog used her teeth to pull Christine Spain, 54, off the tracks as the train approached. While Spain emerged unscathed, Lilly lost a leg.

4:10 p.m. ET: Legendary hairstylist Vidal Sassoon has died, his Beverly Hills salon confirmed to ABC News today. He was 84.

Credit: Alex J. Berliner/AP Photo

3:04 p.m. ET: ABC News EXCLUSIVE: President Obama announced that he now supports same-sex marriage:

Credit: ABC News

"I have to tell you that over the course of several years as I have talked to friends and family and neighbors when I think about members of my own staff who are in incredibly committed monogamous relationships, same-sex relationships, who are raising kids together, when I think about those soldiers or airmen or marines or sailors who are out there fighting on my behalf and yet feel constrained, even now that Don't Ask Don't Tell is gone, because they are not able to commit themselves in a marriage, at a certain point I've just concluded that for me personally it is important for me to go ahead and affirm that I think same sex couples should be able to get married," Obama told "Good Morning America" anchor Robin Roberts in an exclusive interview.

Read the full story HERE. Watch an excerpt of the interview TONIGHT on "Nightline"

1:08 p.m. ET: Losing weight with sinful indulgence? ABC's Nick Watt claims he has lost five pounds in the past eight days on the "Slimness Goal Package" at the Beau Rivage Palace in Switzerland.

"According to the keepers of this apparently counter-intuitive weight loss regimen: I can eat so much cheese for breakfast that it makes me feel sick; I can eat french fries for lunch; I can have a chunk of chocolate mid-afternoon; and I can have two glasses of red wine with dinner."

Read more HERE.

Credit: ABC News

11:34 a.m. ET: Tom Gabel, the lead singer of the punk rock band Against Me!, revealed to Rolling Stone that he's making the transition from man to woman. The magazine said Gabel is the first major rock star to come out as transgender. Read more HERE.

Credit: Tim Mosenfelder/Getty Images.

9:35 a.m. ET: A number of West Virgina Democrats might be blushing. ABC's Elizabeth Hartfield reports that Keith Judd - also known as Inmate No. 11593-051 at the Federal Correctional Institution in Texarkana, Texas - has currently received 40 percent of the vote in the West Virgina Democratic presidential primary. Read more HERE.

Credit: Keith R. Judd / The Beaumont Enterprise / AP Photo