A tornado half a mile wide moves north in Canadian County after having just crossed SH-3, the Northwest Expressway, and moving toward Piedmont, Okla., on May 24. High-powered storms pummeled the midwest starting on May 24 and early May 25, just days after a massive tornado tore up Joplin, Mo. Paul Southerland/The Oklahoman/AP
The remains of the house owned by Scott and M'Lynn McCann that was destroyed by a tornado west of El Reno, Okla., are shown on May 24. Authorities say a series of tornadoes rolled through Oklahoma City and its suburbs at rush hour on May 24. At least four people have been killed. Chris Landsberger/The Oklahoman/AP
Rebecca Watts walks by a car stuck in a tree after being destroyed by a tornado north of El Reno, Okla., on May 24. Violent thunderstorms roared across middle America on May 24, killing seven people in two states, with several tornadoes touching down in Oklahoma. Chris Landsberger/The Oklahoman/AP
Duke looks up from a storm shelter at the Robertson home in Piedmont, Okla., on May 24. Duke actually was in the bathtub during the start of the tornado, and later was found running in a pasture. Sue Ogrocki/AP
Karl Hurst tries to find anything to salvage among the rubble left behind after a tornado destroyed the home of Tom Chronister north of El Reno, Okla., on May 24. Chris Landsberger/The Oklahoman/AP
A house is left as a pile of rubble after being destroyed by a tornado west of El Reno, Okla., on May 24. Chris Landsberger/The Oklahoman/AP
A truck marked with an 'x' lies on its side in a field following a tornado in Piedmont, Okla., on May 24. The 'x usually is an indication that a vehicle has been checked for survivors. Sue Ogrocki/AP
Truck driver Armando Castillo looks at his damaged semi truck after a tornado swept him off of I-40, west of El Reno, Okla., on May 24. Chris Landsberger/The Oklahoman/AP
A house destroyed by a tornado stands in front another, at rear, showing only minor damage, in Piedmont, Okla., on May 24. Sue Ogrocki/AP
An emergency worker stands near the 4-foot diameter tree that fell on a vehicle during a tornado in Kansas on May 24. Two people in the vehicle were killed and a third was sent to Wichita in critical condition. Travis Morisse/The Hutchinson News/AP
An abandoned farmhouse has been reduced to rubble following a tornado in Piedmont, Okla., on May 24. Sue Ogrocki/AP
Harley Voyager removes a vacuum cleaner from the tornado-ravaged home of Jeremy and Crystal Sullins on May 24, after their new double-wide trailer was destroyed by an apparent tornado northwest of Longdale, Oklahoma. Bonnie G. Vculek/ENID NEWS and EAGLE/AP
At least 60,000 mostly Kurdish refugees have entered Turkey since Thursday after Islamic State militants surrounded a Kurdish stronghold in northern Syria. Some are calling for US airstrikes to stop the group's advance.
ByDominique Soguel, Correspondent
Tens of thousands of Syrians have crossed into Turkey in recent days, fleeing an Islamic State offensive that has opened up another front in Syria's civil war as the US weighs a bombing campaign there.