Three children were caught up in an electrical current at a swimming park in Sakarya's Akyazi. The park manager and his son jumped in to save them.
Five people were electrocuted on Friday at a water park in northwest Turkey, including two teenagers and a 12-year-old.
The three youngsters were caught up in an electrical current in the pool in the town of Akyazi in Sakarya province.
The park's 58-year-old manager and his son 30-year-old son were killed when they jumped into the pool to try to save the flailing children.
Employees at the water park, 150 kilometres east of Istanbul, later cut power at the resort.
All five were rushed to a hospital in Akyazi but could not be saved.
Two other people were hurt after touching metal railings near the pool, the report said.
The children who died were aged 12, 15 and 17.
Police officers were conducting an investigation into what caused the electrocutions.
The park lacked a residual current breaker that shuts down power to prevent electrical shocks.
Television footage showed ambulances waiting outside the water park and several people gathered outside the Akyazi State Hospital.