WATFORD CITY, N.D. (AP) — A National Weather Service team is heading to western North Dakota to assess the strength of a tornado that injured nine people and destroyed eight trailers at a workers’ camp in the heart of the state’s booming oil patch.

Meteorologist Todd Hamilton said two meteorologists and an emergency response specialist will on Tuesday rate the tornado that struck the previous evening just south of Watford City.

McKenzie County Emergency Manager Jerry Samuelson says a 15-year-old girl has critical injuries and is being treated at a Minot hospital. Samuelson says he does not know the nature of her injuries.

More thunderstorms are moving through the area, but Hamilton says the threat of more tornadoes on Tuesday is small.