For generations, Mohawks and other Native Americans have built the world's most famous buildings and bridges, including the Empire State Building and the World Trade Center. They work the "high steel," a dangerous profession practiced high above the ground. The skill and craft of ironworking took center stage last month near Syracuse in a sort of ironworker olympics. Ironworkers competed in knot-tying, wrench throwing, and the 30-foot column climb. David Sommerstein reports.