'Nightline' Daily Line, Aug. 24: Empire State Building Shooting

6:19 p.m. ET: UPDATE: The gunman who triggered a wild shootout in front of the Empire State Building today gunned down a former co-worker without saying a word, and stood over his prone victim to pump more bullets into him, police said today.

Read the latest HERE

Credit: Getty Images

4:44 p.m. ET: "No one's ever asked to see my birth certificate," said Romney. "They know that this is the place that we were born and raised."

Romney's comment, made at a rally meant to highlight his hometown roots in Michigan, has set off a firestorm over whather the GOP presidential candidate was making a birther stab at Obama.

Read more HERE and watch the video:

3:01 p.m. ET: UPDATE: Lance Armstrong could lose millions in winnings and endorsements fees if he is stripped of his racing titles, but so far his major sponsors say they have no intention of dropping Armstrong, largely because of his work with the Livestrong Foundation.

Read the latest details HERE

2:09 p.m. ET: Family and colleagues of a freelance reporter from Texas traveling in Syria say they have not heard from him more than a week.

Andrew Tice, 31, a student at Georgetown University Law School and a former Marine, had traveled to Syria for several months to report on the 17-month uprising, filing for a number media outlets including the Washington Post and McClatchy newspaper group.

Full story HERE

11:58 a.m. ET: ABC meteorologist tweets about the latest news with Tropical Storm Isaac:

Credit: National Hurricane Center

11:01 a.m. ET: ABC News senior White House correspondent Jake Tapper tweets:

10:09 a.m. ET: BREAKING: A gunman who opened fire outside New York City's Empire State building has been killed, the NYPD told ABC News, but not before an bystander was gunned down.

This story is still developing, read the latest HERE

Credit: ABC News

8:17 a.m. ET: It's being called one of the greatest frauds in the history of sport: Seven-time Tour de France winner Lance Armstrong used performance enhancing drugs to cheat his way to the top, according to the U.S. Anti-Doping Agency, whose allegations will no longer be challenged by Armstrong.

Watch the "Nightline" piece HERE: