Threatening clouds continue to move through southern Tarrant and Dallas counties after a tornado swept through Lancaster, Texas on Tuesday, April 3, 2012. Tornadoes tore through the Dallas area Tuesday, peeling roofs off homes, tossing big-rig trucks into the air and leaving flattened tractor trailers strewn along highways and parking lots. (AP Photo/The Fort Worth Star-Telegram, Ron Ennis) MAGS OUT