Police in Halton Region are investigating the death of a three-year-old boy who was pulled from a backyard pool in Oakville on Saturday.

The incident happened at a residence in the area of Speers Road and Third Line.

Halton Regional Police Service (HRPS) said emergency responders were called to the scene shortly after 7 p.m.

According to police, there had been a “celebratory gathering of several adults and children at a private residence and the child had gone underwater and apparently undetected for an undetermined period of time.”

Investigators said adults immediately began life-saving measures, which were continued by emergency services personnel once they arrived at the scene.

“Despite efforts to revive the child, sadly he was pronounced deceased at hospital,” HRPS said in a May 28 news release.

The name of the child as well as further details about those who attended the gathering are not being released, police said.

Halton Regional Police Service’s Homicide Bureau in partnership with the Coroner’s Office, investigates all deaths involving children under the age of five.

At this point, no charges have been laid and police said that they have also determined there is no criminality in this case.