Two people have been pronounced dead at the hospital after being pulled from the waters of Hidden Lake in Green Oak Township.
Two other people were treated at the scene for hypothermia and released. One of those victims was found on the shore, the other was on top of an overturned boat.
Police say the four were part of a crew that was pulling swim buoys out of the lake.
The two people pulled from the water were taken to U of M Hospital in extremely critical condition, but were later pronounced dead.
Officials say they were not in the boat, but tried to rescue the boat crew when their craft overturned.
