A man pulled from a pond near downtown Maple Grove Friday night had been underwater for at least an hour before divers located him in the dark water where ice partly covered the surface.

The man, identified only as a metro resident, was unconscious when taken to Maple Grove Hospital, said Lisa Kiava, a spokeswoman for the Hennepin County Sheriff’s Office. His condition was not immediately available.

A witness had called 911 at 8:05 p.m. to report that the man walked out onto the pond and fell in. The pond, which is deep in the center, is behind Great River Energy on Elm Creek Boulevard, just off Main Street, Kiava said.

Maple Grove police and fire departments, North Memorial Ambulance and the sheriff’s office responded. Between 9 and 9:30 p.m., they pulled him from the depths and worked on him before taking him to the hospital, Kiava said from the scene.

At the time, lots of people were out enjoying the warm spring night in the area, which has walking and bicycle paths, but investigators remained puzzled about what led the man onto the receding ice.

Said Kiava: “The detectives are pursuing the case, and that’s one of the questions they’re asking, is what led up to this, that he would walk into the pond?”