President Obama visited the new 1 World Trade tower Thursday, hailing the rebuilding and signing one of the final steel beams that will be added to the building. "We remember. We rebuild. We come back stronger!" Obama wrote. He and the first lady went up to the 22nd floor and stared down at the National September 11 Memorial below. "It's beautiful," he said of the two massive fountains that mark where the twin towers once stood. "You don't expect how powerful it is."