A truck trailer park has been destroyed after a tornado struck in Dallas County in Texas.
Ten to 12 tornadoes touched down during a massive storm that brought chaos from high winds, rain and hail to the nation's fourth most populous metropolitan area, said National Weather Service meteorologist Jesse Moore.
Many of the 6.3 million area residents were forced to scramble for safety as the storm bore down during the early afternoon, when schools and workplaces were open.
Seven people were injured in the suburb of Arlington, police said. Most suffered only minor injuries but one person hit by a falling tree was in critical condition, said Arlington police spokeswoman Cheryl Carpenter.
In one of the hardest hit areas south of Dallas, Lancaster, tornadoes damaged 300 structures.
Of the 10 people injured in Lancaster, two of them were severely hurt, said Lancaster police spokesman Paul Beck.
There were no immediate reports of injuries but the National Weather Service declared a tornado emergency.