NYC Blast Shows Infrastructure Problems

With a blast that made skyscrapers tremble, an 83-year-old steam pipe sent a powerful message that the miles of tubes, wires and iron beneath New York and other U.S. cities are getting older and could become dangerously unstable.

The steam conduit that exploded beneath a Manhattan street at the height of rush hour Wednesday, just a block from Grand Central Terminal, was laid when Calvin Coolidge was president and was part of a system that began providing energy to city buildings in 1882.

Investigators are still trying to determine what