Hurrricane Isaac - Photo Gallery 39/70

A person walks by a sign warning about Hurricane Isaac, in Key West, Fla., Sunday, Aug. 26, 2012. Isaac gained fresh muscle Sunday as it bore down on the Florida Keys, with forecasters warning it could grow into a dangerous Category 2 hurricane as it nears the northern Gulf Coast. (AP Photo/Alan Diaz) ORG XMIT: FLAD107