CHICAGO (WGN) – Authorities are conducting a "death investigation" after a severed head was discovered Friday in Chicago's McKinley Park Lagoon.

A man working at the lagoon made the grisly discovery this morning. The groundskeeper was working to clean trash and found a bag holding the severed human head near the lagoon.

Police were called and closed the park to the public. Cadaver dogs have searched for other body parts in the area.

Community activist Andrew Holmes says the investigation indicates the killing was recent.

"It looks like the head is not decomposed," he said. "If this is indeed a human remains dead, then some family's going to get the unfortunate news about their loved one."

At this point, the identity of the victim is not known, but one source said it appeared to be an African-American male.

Holmes says the next step in the investigation is to drain the lagoon to see if the rest of the body is hidden under water.