Canadian authorities are evacuating tens of thousands of residents in Alberta as a massive wildfire rages around Fort McMurray, the capital of the country’s oil sands region. Some 80,000 people were forced to flee the city Tuesday as the 6,540-acre blaze destroyed homes and Alberta officials called on other provinces for help. In Edmonton, officials were scrambling Wednesday to prepare for the arrival of some 20,000 refugees. The fire, which was discovered May 1, spread onto the main road into Fort McMurray from the south. Alberta Premier Rachel Notley said blaze prompted the “biggest evacuation we have seen in the history of the province,” but added there were no casualties reported in the fire. Footage showed flames and smoke billowing over the city as traffic heading north appeared gridlocked. Firefighters, nine air tankers, and more than a dozen helicopters were deployed to battle the fire, officials said.