From the wiki on the Ft. McMurray fire:
On May 1, 2016, a wildfire began southwest of Fort McMurray, Alberta, Canada. On May 3, it swept through the community, destroying approximately 2,400 homes and buildings and forcing the largest wildfire evacuation in Albertan history.
Bottom ticked the recent low in USD/CAD on May 3rd to the day:
Now we can observe what happens to USD/CAD as the fire situation is abated and previous rate of oil production returns to the region.