Debris is scattered Tuesday after a tornado in Watford City, N.D. Authorities say at least eight trailers were destroyed Monday evening when the twister tore through a camp where oil field workers stay. Nine people were injured, including a 15-year-old girl critically.

WATFORD CITY, N.D. — A rare North Dakota tornado that critically injured a 15-year-old girl and hurt eight other people at a workers’ camp in the heart of the state’s booming oil patch packed winds that peaked at 120 mph, the National Weather Service said Tuesday.

The twister touched down Monday night at a camp just south of Watford City and damaged or destroyed 15 trailers. The 15-year-old, who was from out of state and visiting an aunt and uncle, was flown to a Minot hospital. She was in an intensive-care unit with a head injury but expected to survive, McKenzie County Emergency Manager Jerry Samuelson said Tuesday.

Samuelson did not release the girl’s name or where she lives.

Eight other people were treated at a Watford City hospital for less serious injuries. The American Red Cross said eight residents spent the night at a shelter at Watford City’s Civic Center and several families were among those displaced.

Tornadoes are rarely reported in McKenzie County, with only 14 since 1950, with no fatalities, according to weather service data. Monday’s tornado, which hit about 7:50 p.m., was an EF-2 in strength on the 0-to-5 enhanced Fujita or EF scale, the weather service said Tuesday afternoon.

Preliminary information suggests the winds of the twister peaked at 120 mph, the weather service said. A second brief tornado possibly occurred in the area based on eyewitness accounts, it said.

National Weather Service meteorologist Todd Hamilton said two meteorologists and an emergency response specialist left Bismarck at daybreak Tuesday to survey the damage at the camp.

Plywood was scattered along with other debris across several hundred square feet at the site.