CHICAGO (CBS) — A nighttime group swim turned deadly after one person drowned early Wednesday.

Police responded to the 1000 block of North Lake Shore Drive around 4 a.m. after the group lost track of one of their friends.

An adult male was pulled from the water near Oak Street beach and was transported to Northwestern Memorial Hospital, where he was pronounced dead.

Witnesses told CBS 2 that five people went into the lake for a swim.

The man was later found floating in the water.