Large Tornadoes, Damage Reported in Dallas Area DALLAS (AP) - 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. The National Weather Service confirmed at least two separate "large and extremely dangerous" tornadoes. Several other developing twisters were reported as a band of violent storms crept through the metropolitan area, destroying mobile homes and forcing hundreds of flight cancellations at Dallas-Fort Worth International Airport. There were no immediate reports of injuries. "The officers were watching the tornadoes form and drop," said Kennedale police Chief Tommy Williams. It was pretty active for a while. Highway video cameras showed a large, dark funnel cloud moving on the ground not far from a busy Dallas interstate early Tuesday afternoon. Big-rig tractor trailers crumpled like soda cans littered an industrial parking lot, and flattened trailers clogged the sides of highways and access roads. In Lancaster, south of Dallas, television helicopters panned over exposed homes without roofs and flattened buildings. Broken sheets of plywood blanketed lawns and covered rooftops. Residents could be seen walking down the street with firefighters and peering into homes, looking at the damage after the storm passed. Devlin Norwood said he was at his Lancaster home when he heard the storm sirens. He said he made a quick trip to a nearby store when he saw the funnel-shaped tornado lower, kick up debris and head toward his neighborhood. I didn't see any damage until I got back home. We had trees destroyed, fences down, boards down, boards penetrating the roof and the house, shingles damaged," said Norwood, 50, an accountant and graduate student. The storm pushed cars into fences and toppled trees. Branches and limbs scattered across lawns and residential streets, and in one driveway, a tow-behind RV was left torn apart and crumpled. "Obviously we're going to have a lot of assessments to make when this is done," Dallas County spokeswoman Maria Arita said. Dallas Police spokeswoman Sherri Jeffrey said an apparent twister also touched down and caused damage within the city's southern limits, though the extent was not immediately known. American Airlines canceled nearly all its departures from its hub at DFW on Tuesday evening and diverted others to different airports. Spokeswoman Andrea Huguely said the airline also was pulling dozens of planes out of service to inspect them for hail damage. DFW spokesman David Magana said there were no reports of damage to the airport itself. Magana said employees pulled passengers in the terminals away from glass windows during the storms and directed them to stairwells, stores and restaurants in the inside area of the airport. Flights also were canceled at Dallas Love Field, which is a big base for Southwest Airlines. That airline canceled more than 45 flights in and out of the airport by Tuesday evening. Associated Press writers Terry Wallace and David Koenig in Dallas and Betsy Blaney in Lubbock contributed to this report.