Six years of World War II, and the Slovak National Uprising, significantly impacted peaceful pre-war life in the Kľak valley. The Slovak National Uprising mostly marked the destiny of the Ostrý Grúň and Kľak municipalities, the sites of one of the worst war crimes committed against civilians. The events entered the history books as "Bloody Sunday 1945", and are commemorated by memorial rooms in both villages and monuments of remembrance. The memorial in the village of Ostrý Grúň is called the Statue of a Mother Defending a Child carved in 1965. The sculpture was created by J. Chrobák and J. Podzimková-Mráčková. At the memorial, reverence events are annually organized to commemorate this tragic incident in the history of the village.
