(IDEX Online) - The plane that crashed last Wednesday (27 December) in Canada's Northwest Territories was flying workers to build the winter road that supplies Ekati, Diavik, and Gahcho Kue diamond mines with vital supplies from February to March every year.Canada's Transportation Safety Board is investigating the cause of the accident, involving a 49-year-old Air Tindi de Havilland DHC-6-300 light aircraft, which came down on Lac de Gras, about seven miles from the Diavik diamond mine.Two people suffered "moderate to serious" injuries and six others had minor injuries. All eight passengers and two crew were rescued by helicopters after a night in an emergency heated tent.The Tibbitt to Contwoyto Winter Road (TCWR) is a joint venture between the companies operating three diamond mines in the area - Rio Tinto (Diavik), Burgundy (Ekati) and De Beers/Mountain Province (joint venture, Gaucho Kue).The 300-mile ice road - the longest in the world - is built mostly over frozen lakes. Despite the cost of constructing a new road every winter, it is the cheapest method of delivering fuel, construction materials, heavy mining equipment, and explosives to the diamond mines during the winter months.In a statement, TCWR said workers were heading to an accommodation camp to begin construction of the 2024 winter road when their plane came down."TCWR wishes a speedy recovery to the passengers who were injured and has offered its assistance to passengers and their families, should they need it," the company said."TCWR will collaborate with the Canadian Transportation Safety Board, supplying any information they need for their investigation. "After assessing the situation, TCWR does not expect the incident to affect the construction of the winter road, which will be completed, as scheduled, in the first half of February."Pic of the winter road courtesy TCWR.