[美国广播公司世界新闻(2011-2季)].110413_wn.docVIP

April 13, 2011 George: Tonight on World News, dozing off. Another air traffic controller asleep on the job. We’re going to need to land. Roger. Landing will be at your own risk. We press the nation’s top transportation official for answers. Senseless act. A mother drive herself and three children into a river to death. How one son survived and what makes a parent crack? Popping pills. The number of Americans taking diet supplements every day is skyrocketing, but did they really work and its taking them at risk. And angel in the outfield. The little girl lost in the Tucson shooting remembered by her teammates. How her friends are fielding her dreams? From ABC News headquarters, this is ABC World News with Diane Sawyer. Reporting tonight, George Stephanopoulos. George: Good evening. Believe it or not, it happens again. Earlier this morning, another air traffic controller asleep at the switch while a flying ambulance with a sick passenger on board circled overhead, desperately seeking to land. It never came. The pilot took the risk and landed anyway. While everyone on board is ok tonight, the rest of us are wondering what’s going in those control towers and can we be sure our skies are safe. The transportation secretary standing by to answer those questions, but we start with our aviation correspondent Lisa Stark who in on the story again tonight. Good evening, Lisa. Reporter: Good evening, George. Well, this is now the latest in a string of incidents like this. Air traffic controllers falling sleep on the job. Just last moth, the government said it will not tolerate such behavior. And yet, here we are again. Around 2:00 a.m this morning in the sky above Reno, a pilot carrying a serious ill patient is trying to land at the airport there, trying to call the towel. No one is answering. Can’t see to get a hold of the tower here. I think I’m going to try and give them another call. Reporter: The pilot then called the next controller he talked to in Sacr