As Iraqi and Kurdish troops close in on the ISIS stronghold of Mosul in Iraq, militants fleeing the region have been sabotaging oil-producing facilities and setting oil wells ablaze, blackening the skies with oily soot for miles. Residents trapped in the area, or attempting to return to their homes, are experiencing health problems related to the smoke, and shepherds are unable to sell the wool of their blackened sheep. As troops are able to stabilize some areas, firefighters attempt to tame the fires before they spread to already-damaged villages nearby.