Korostatyatin was a predominantly Polish village, with a few Ukrainian families living there; according to the census of 1.03.1943, it had 944 inhabitants.

The biggest UPA attack on the Poles living here took place on the night of 28-29 February 1944. The self-defence from Korostatyń, initially surprised, however, put up a resistance that saved most of the villagers. The fighting stopped only in the morning, when a Polish partisan unit, stationed in Puzniki, 12 km away, came to the rescue. According to witnesses, about 150 people were murdered.

The murdered were buried on 2.03.1944 in a common grave in the Korossiatyn cemetery, a few or a dozen people were buried in family graves. Until 2007, in the Korossiatyn cemetery, to the right of the entrance there was a wooden cross, without any inscriptions, on the grave of the murdered. In 2011, by order and with funding from the Council for the Protection of Remembrance of Struggle and Martyrdom, a permanent commemoration of the grave was made of light granite, consisting of a cross and two semi-recumbent plaques with the names of the victims. One of them bears inscriptions in Polish and the other in Ukrainian. The inscription reads: "They departed to God in tragic / circumstances on 28.02.1944 / [list of 122 names] / Prosza o modlitwe!" (the inscription in the Polish version contains linguistic errors).