Winter storms hit U.S.

This photo provided by the Iowa State Patrol shows the scene of a 25-vehicle pileup that killed three people Thursday, Dec. 20, 2012 north of Des Moines, Iowa. Authorities said drivers were blinded by blowing snow and didn’t see vehicles that had slowed or stopped on Interstate 80 about 60 miles north of Des Moines. A chain reaction of crashes involving semitrailers and passenger cars closed down a section of the highway. (AP Photo/Iowa State ... more 

This photo provided by the Iowa State Patrol shows the scene of a 25-vehicle pileup that killed three people Thursday, Dec. 20, 2012 north of Des Moines, Iowa. Authorities said drivers were blinded by blowing snow and didn’t see vehicles that had slowed or stopped on Interstate 80 about 60 miles north of Des Moines. A chain reaction of crashes involving semitrailers and passenger cars closed down a section of the highway. (AP Photo/Iowa State Patrol) less