Oil workers film tornado in North Dakota
27 May 2014 Last updated at 15:45 BST
A group of oil workers have escaped a tornado, moments before it struck their camp in North Dakota, US.
At least 15 trailers were damaged or destroyed south of Watford City on Monday, with a 15-year-old girl suffering critical injuries.
Rescue crews are continuing to search through debris at the camp.
Dan Yorgason captured this footage as he fled.