

In between bites of a hot dog, U.S. President Barack Obama explains the finer points of the zone defense to British Prime Minister David Cameron as they watch the Western Kentucky Hilltoppers take on the Mississippi Valley State Delta Devils in the first round of the 2011 NCAA men's basketball tournament on March 13 in Dayton, Ohio.

A caution barrier seals off an accident scene at the Sanda bridge construction site on March 13 in Loudi, in China's Hunan province. A part of the Sanda bridge, which cost 110 million yuan (about $17.36 million), collapsed on Monday evening, though no casualties were reported.

New York's Brooklyn Bridge by night. A crane pulled by a tug boat on the East River slammed into scaffolding beneath the bridge on March 13. According to reports, no damage was done to the structure of the bridge.
