Three adults have been arrested after two boys’ experimentation with drugs they found in the house ended with one of them dead of an apparent overdose.

An autopsy will determine the cause of death of Zackary Foster, a 13-year-old student at Washington, Missouri, Middle School, KMOV reported.

Washington Police Sgt Steve Sitzes said Foster was spending the night at the home of a 12-year-old friend on Saturday. Sometime during the night, Sitzes said, the two took drugs they’d found in the house.

When the younger boy woke up around 9 a.m. on Sunday, he found Foster unresponsive.

Police arrested the 46-year-old mother and 59-year-old stepfather of the 12-year-old and a 62-year-old man renting a room in the homes basement on drug-related charges, Sitzes said, and more charges could be filed when the investigation is concluded, including manslaughter and endangerment of a child’s well-being.

Sitzes said investigators found a large amount of prescription drugs as well as some illegal drugs in the home, but it’s unclear what kind of drugs the boys took.

The Missouri Department of Social Services took two children — the 12-year-old and his 7-year-old half-sister — into protective custody.

The school district where Foster attended said it planned to have grief counselors available for students and staff this week.

Sitzes said the two boys frequently spent time together and that it was not unusual for Foster to spend the night at his friend’s house.

“I know her [deceased teen’s mother] son had spent the night there several nights in the past. I don’t know how much she knows about the family itself,” Sitzes said, adding that the mother had taken multiple steps to keep her son safe.

“She had on her son’s phone an app that she would set up geofences of where he was at, and it would send her alerts that he was outside the geofence. She had that, she knew where he was at in the home, and knew what time he had gotten there, and that he hadn’t left, but tragedy still struck,” Sitzes said.

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