A Memorial Day tornado ripped through an oil field camp in North Dakota, injuring nine people and destroying trailers where workers had been living, according to emergency officials.

Large hail and heavy rain accompanied the twister which touched down at around 7:50 p.m. at a camp about 5 miles south of Watford City in the western part of the state.

Emergency crews sifted through a large amount of debris at the camp, but were confident that nobody was missing.

The tornado descended so quickly it was difficult for people in the area to take shelter. One critically injured person was taken to a hospital in Minot.

Some workers heard there were 3 different touchdowns after the tornado warnings sounded. The National Weather Service will try to determine whether is was the same tornado touching down 3 times or if it was 3 separate events.

The Associated Press contributed to this report