By Joshua Santos, Writer Investigators face a significant challenge as they examine what sparked a mammoth fire at a popular First Nations restaurant recently. Professionals with the Office of the Fire Marshal say they can’t enter the Burger Barn on Fourth Line after a fire ravaged the building compromising the roof. “It was determined that the fire caused significant structural damage to the building,” said Sean Driscoll, spokesperson for the Office of the Fire Marshal to Turtle Island News. “For the safety’s sake of the investigators, no one will be entering the building while we wait for heavy equipment to arrive to provide the structural integrity necessary to safely enter the building in order to continue with the fire investigation.” The building, reminiscent of a large red farm barn, appeared…