The Thunder Airlines Beechcraft A100 aircraft departed Moosonee, Ontario (CYMO) destined for Fort Albany, Ontario (CYFA). The flight was conducted under VFR conditions. During the approach the first officer selected the landing gear down, however there was no movement from the landing gear and no gear lights illuminated. The flight crew followed the QRH procedures and manually lowered the landing gear, and observed three green lights, indicating the gear was down and locked. The flight returned to CYMO, and the passengers were briefed on the situation and a landing was performed on runway 24. During touchdown, the flight crew heard an unusual noise from the left main gear location and felt the left wing begin to drop. The left main gear green indicator light also extinguished. The captain immediately aborted the landing, applied engine power, and became airborne, reportedly without any other parts of the aircraft coming into contact with the runway. The flight crew decided to divert to Timmins Victor M. Power Airport (CYTS), ON, a main base for the operator with emergency services, since the aircraft had sufficient fuel and VFR conditions existed throughout the route. The flight crew declared an emergency and proceeded to land on runway 21. The aircraft touched down on the nose and right landing gear and settled on the left side of the belly pod. The aircraft skidded until it stopped at the intersection of runway 10/28. All occupants exited the aircraft and no injuries were reported.