Audio Slideshow: Inside Eisenhower Lock

The locks and channels of the Great Lakes-St. Lawrence Seaway system are getting old. Some were built more than 75 years ago. The U.S. and Canada are conducting a multi-million dollar study to determine how to keep the aging waterway functional, so ships can continue to haul cargo between the Great Lakes and the Atlantic Ocean. While the Seaway is closed in winter, workers empty the locks of their water for annual maintenance. David Sommerstein climbed eight stories down to the bottom of the Eisenhower Lock on the St. Lawrence River near Massena to see how it's aging.