Final steel beam lifted at 4 World Trade Center
Four World Trade Center
A construction worker signs the ceremonial last beam before it is hoisted to the top of Four World Trade Center, Monday, June 25, 2012. The 72-floor, 977-foot tower is scheduled to open late next year. It's expected to be the first tower completed on the 16-acre site since the 9/11 attacks. (AP Photo/Mark Lennihan)






