More than half of the Netherlands lies below sea level. To protect these parts against the sea people have built dikes. In the night of February 1st 1953 these dikes were proofed not to be strong and high enough against the violent forces of the sea. The waves destroyed the dikes and flooded the land behind them. Many of the inhabitants were surprised and had no time to escape to the attics and other high points of their houses. Others saw the waters coming on their way to their homes and were washed away.