On July 10, 1887, a dam breaks in Zug, Switzerland, killing 70 people in their homes and destroying a large section of the town.
The dam at Zug was 80 feet high and made of concrete. When the dam was built, concrete-making and setting techniques were not as advanced as they are today. The water pressure on the dam slowly eroded the concrete, finally causing it to collapse on July 10.
The resulting wall of water was so powerful that it picked up and washed away large farm animals. It uprooted trees and carried them downstream toward the town. Unsuspecting patrons at a cafe lost their lives when the roaring water and debris suddenly descended upon them. Rescue boats launched to assist people caught up in the sudden flood were ineffective, as some of those on the boats drowned when they capsized in the roiling waters.