Over at 4 World Trade Center in lower Manhattan, Mother Nature is throwing the ironworkers for a loop: wind and scorching summer temperatures are making it difficult to set the heavy steel on the tower's last four floors. Meanwhile, across the East River in Brooklyn, the ironworkers at Brooklyn's new Barclays Center are setting the final steel for the arena’s exciting cutting-edge entryway. But when the supporting towers are removed, will the enormous cantilever stand on its own?