CHICAGO (WGN) — A woman is in custody on Saturday morning and a homicide investigation is underway after officers say she allegedly drowned a baby in the lake on Friday night.

According to police, officers first responded to the scene around 9:45 p.m. following a service call about a 31-year-old woman who had been found in Lake Michigan in the 7000 Block of S. South Shore Drive, near South Shore Beach.

After arriving on the scene, further investigation indicated that the woman had allegedly drowned a 1-year-old boy in the lake.

Following the discovery, officers took the woman into custody and transported her to the hospital.

Shortly after the woman was arrested, the CFD Marine Unit recovered the body of the child, and he was pronounced dead.

It remains unclear what led to the incident, and an investigation is now underway.

Authorities have not announced charges against the woman or provided details on whether she was related to the victim.