|Cause of death||Hypothermia or drowning|
|Date|| July 26, 1959|
|Location(s)||Vaindloo, Soviet Union|
Matvievsky, who was stationed on the island with two other navy sailors to track ship traffic, took a machine gun and shot dead his colleagues, the lighthouse keeper, the keeper's wife and two children, as well as the mother of a second family. He spared the two children of the second family who were discovered a few days later by their father, when he returned from the mainland.
After the shooting Matvievsky escaped on a motor boat, but eventually either drowned, or froze to death. His body was found on August 3 on the coast of the Finnish island Musta-Hevonen near Kotka.