The story of an eight year old boy from Haarlem
), who saw a small leak in a dike
. In order to avoid a damburst
, the boy stopped the hole by sticking his finger
into it. Unfortunately, there was no one to help the little fellow, so he stayed on guard the entire night. Haarlem was saved from a flood
This (most likely fictional) story was written by American writer Mary Mapes Dodge (1830-1905) in the book Hans Brinker; or, The silver skates. Hans (and his sister Gretel) play an important role in the book, but he is not the boy who rescued Haarlem. The actual hero's name is Peter, the son of a sluicer.
The book Hans Brinker is available as e-text on Project Gutenberg.