At 2:30 p.m., the last wagon of a grain train derailed. Several minutes later, it was struck by a freight train travelling in the opposite direction on the opposite track and comprising 100 tank wagons loaded with crude oil. Twenty of the freight train’s wagons tumbled onto their sides, spilling 1500 m³ of crude oil, setting off a chain of explosions, and sending an enormous plume of black smoke into the air. The authorities evacuated the 2400 inhabitants of the town of Casselton (less than 2 km from the accident) who were threatened by the smoke. They let the wagons burn, then poured sand over the spill to soak up the oil. The inhabitants returned to their homes the following day. Damage was estimated at €4.5m. Although the authorities stated that the oil had not reached any waterways or drinking-water sources, they were concerned that the spring thaw could cause the oil to seep underground. Both trains were travelling within the authorized speed limits when the accident occurred. The oil train was hauling sweet crude from North Dakota’s Bakken formation, which was the same type of oil involved in the Lac-Mégantic derailment in Canada (see 44026).