Water cribs in Chicago

The Two-Mile Crib was constructed as part of a scheme by Ellis S. Chesbrough in 1865, to help with the purification of the water because of damage caused by the city dumping sewage into the lake.

This kept the crib at a temperature of 70 °F (21 °C) and allowed plant workers to reside there during the winter, who helped to stop the formation of ice.

The crib was equipped with a navigational warning light atop a steel-skeleton lighthouse and a fog bell that tolled every 12 seconds when needed.

On the morning of January 20, 1909, a fire broke out on the Intermediate Crib in a wooden barracks which housed tunnel workers.

The suit charged that the engineers, Alvord, Burdick & Howson, were negligent for advising the city that it was safe to drain the tunnels.

As a result, the city spent $5.3 million to fill in a portion of the tunnel under Lake Shore Drive to prevent a possible additional collapse.

Work on the 90-foot (27 m) diameter crib began in 1915 and was completed May 1, 1918 after a delay to correct an out-of-plumb structure due to settling.

The superstructure is rough-hewn granite block atop a steel caisson enclosing a 40 feet (12 m) diameter inner well chamber.