Storms damaged or destroyed more than 20 homes and knocked out power for thousands of people in northern Texas.
One person suffered minor injuries in the violent weather late Monday, authorities said.
Denison Police Lt. Billy Shaw told The Associated Press that "it did appear to be a tornado, by looking at the damage."
National Weather Service representatives planned to review the damage to confirm whether there was a tornado.
Shaw said about 5,000 homes and businesses were without electricity early Tuesday in the Denison area. He estimated two or three homes were destroyed there.
In addition, Sherman Fire Department Chief Jeff Jones says at least 2,000 customers were blacked out in his town and northern Grayson County and at least 20 homes were damaged.
"Numerous roofs are gone," Shaw said.
