Article Photos: WTC workers scrawl graffiti of defiance, hope 5/12

FILE- This Aug. 2, 2012 file photo shows President Barack Obama's message and signature on a steel beam at One World Trade Center in New York. The presidentâs words will join those of numerous construction workers at the site who left personal messages on the beams, when they will be sealed behind the facade of the buildings as they progress toward their 2014 completion date. (AP Photo/Mark Lennihan, File)