North Dakota Tornado filmed by oil workers before it destroys their base camp

The men swear in the video as the tornado thunders towards to them

A still from a video provided by Dan Yorgason shows a tornado in a worker's camp near Watford City, N.D., in the heart of the state's booming oil patch. The tornado injured nine people, including a 15-year-old girl who suffered critical injuries, and dama (AP Photo/Dan Yorgason)

The moment a ferocious tornado churned across North Dakota on Monday evening, and injured nine people, has gone viral online in a dramatic video.

The footage was shot from the perspective of a group of oil workers as they fled the twister, before it destroyed their base camp in the heart of the state’s oil fields.

Under the YouTube video, user Dan Yorgason has warned viewers: "LANGUAGE! We were afraid for our lives, so, yes, we swore. A lot. You have been warned!"

Viewers can hear the men swearing and nervously laughing as they gaze at the twister in awe.

US investigators have since headed to the northern state to assess the strength of the tornado that hospitalised a 15-year-old girl. Authorities said early on Tuesday that the girl, who was visiting an aunt and uncle, was in an intensive-care unit but was expected to survive.

The American Red Cross said on Wednesday that eight residents spent the night at a shelter and that several families were among those displaced.

Warning: strong language

Tens of thousands of people searching for work have been attracted to the North Dakota oil fields in recent years. Many live in hastily assembled trailer parks, known as man camps, housing pre-fabricated structures that resemble military barracks. Some companies rent blocks of hotel rooms for employees, while others sleep in their cars or in tents.

The growth of temporary housing also means there is more of a chance for death, injury and destruction from tornadoes, meteorologist Ken Simosko told reporters.

“People living in trailers creates a very dangerous situation because there is no protection,” Simosko said.