A train carrying oil derailed and caught on fire Wednesday in Heimdal, North Dakota. As many as 10 cars are on fire, according to emergency services in the area. It was unclear whether the train exploded or merely caught fire. The nearby town of 40 people has been evacuated and no injuries have been reported so far. An investigation team has been sent to the site to find out what caused it. Oil-train accidents have been on the rise as more petroleum is transported across the country thanks to the fracking boom.