The tornado that touched down in North Dakota on Monday night injured nine people, one critically, when it struck an oil worker camp, officials there say.
McKenzie County Emergency Management Director Jerry Samuelson told the Associated Press that the tornado damaged about 15 trailers housing workers about 5 miles south of Watford City and 30 miles southwest of Williston, the center of the state's oil boom.
The critically injured person was taken to a hospital in Minot, N.D., for treatment, Samuelson said, adding that all the people at the oil worker camp had been accounted for.
"Obviously, we're very fortunate there are no deaths, to our knowledge," he said.
Meteorologists from the National Weather Service were en route to the area early Tuesday to survey the damage and assess the strength of the tornado.
Residents captured the destructive weather system in video and photos.
North Dakota's oil boom "has led to a population explosion in western North Dakota," AP notes, with many oil workers residing in "hastily-assembled trailer parks or man camps, which contain pre-fabricated structures that can resemble military barracks." Some oil companies rent blocks of hotel rooms for employees. Other workers sleep in their cars or even tents.