The aircraft took off from Winnipeg at 1438 CST for a flight to Sandy Lake, St. Theresa Point, Island Lake and return to Winnipeg. On arrival at Sandy Lake at approximately 1549, the crew attempted to land but were unable to because of the low ceiling and visibility. They then diverted to St.Theresa Point, landing at 1630. The flight departed St. Theresa Point for Sandy Lake at 1720. The aircraft landed at approximately 1745 at Sandy Lake, where 22 passengers deplaned while four remained on board; the aircraft was not refuelled or otherwise serviced at Sandy Lake. During the stop, both engines were shut down. The aircraft took off from runway 29 at Sandy Lake at approximately 1805 and entered a right turn. Witnesses indicate that the aircraft appeared to fly at a lower than normal height throughout the turn. After turning through approximately 120 degrees, the aircraft descended into 100-foot trees and crashed. The aircraft struck the ground about 1 nm northwest of the airport. PROBABLE CAUSE: “After take-off, the crew most likely lost situational awareness and, as a result, did not detect the increasing deviation from their intended flight path. Contributing to the loss of situational awareness was the lack of AC power to some of the flight instruments; the reason for the lack of AC power could not be determined.”