In 1953 a break in the dikes and seawalls in the Netherlands killed 1,835 people and forced the evacuation of 70,000 more. Ten thousand animals drowned, and 4,500 buildings were destroyed. To prevent such a tragedy from happening again, an ambitious flood defense system was conceived and deployed, called the Delta Works (Dutch: Deltawerken).
http://www.deltaworks.org/ English website about the DeltaWorks. Includes many photos, videos, etc.