A 9-year-old child drowned in the Leppäkorvi inland swimming pool in Vantaa on Friday at five o'clock in the afternoon.
Police say in a statement that the child was on the beach spending time with a group of his peers and older children.
All were minors.
There were no organized swimming controls on site.
Police first learned of the missing child on the beach.
The bystanders found the child dead in the water at about 5:30 p.m.
In his release, the police thank active bystanders for their exemplary conduct in the search.
At the time of the incident, there were a lot of eyewitnesses on the beach, according to police.
The City of Vantaa Social and Crisis Emergency Service provides acute crisis assistance on 09 8392 4005. The number is available 24 hours a day.