My Bloody Valentine (1981)

Valentine's Day is coming around and the young people of the small mining town of Valentine's BLuffs are organising a party. A few decades earlier an explosion at the mine trapped six miners underground. One, Harry Warden, survived, though in a deranged state. Warden is sent to a mental hospital but escapes and murders those he deems responsible for the mine accident. Now people are being brutally murdered again, and the townsfolk suspect that it is the work of Harry Warden.