Investigators are working to determine what caused a massive blaze at a townhouse complex that was under construction in Cochrane and say damage to the structures is estimated to be over $2 million.

Emergency crews were called to a large fire in the community of Fireside at about 2:15 a.m. on June 6.

Two townhouses were completely destroyed by the fire and a third sustained significant damage to the exterior.

The heat from the fire was so intense that homes across the street were also impacted.

"Because this fire was so large and has a damage estimate in excess of 2 million dollars a thorough investigation is underway, which can take time" said Constable Kary Moore with the Cochrane RCMP in a statement.

RCMP in Cochrane are appealing to the community for help to determine what caused the fire and are asking anyone who noticed suspicious activity in the Fireside area in the early morning hours of June 6 to contact RCMP at 403-851-8000.