While on a cargo flight, the crew encountered poor weather conditions with limited visibility due to fog. The pilot-in-command apparently decided to reduce his altitude to maintain a visual contact with the ground when the aircraft hit the icy surface of a lake located near Manicouagan. The airplane was destroyed and two crew members were killed, the third occupant was injured.
Probable cause (official findings): The pilot became lost and descended below the minimum en-route altitude in an attempt to establish his position.