Nebraska cleans up after tornadoes injure two

(Reuters) - A pair of tornadoes destroyed homes, toppled train cars and downed power lines in central Nebraska, injuring two people, as the southern U.S. plains braced for storms that could bring tornadoes and flooding, authorities said on Monday.

One person had to be extricated from a collapsed home near North Platte late on Sunday, and a truck driver whose rig was swept off a highway was also taken to the hospital. Neither suffered life-threatening injuries, said Al Berndt of Nebraska's emergency management agency.

"There were two tornadoes sighted south and west of North Platte in a sparsely populated area," Berndt said. "Two or three homes were destroyed, and several others damaged."

Some 15 rail cars were knocked over by a twister in Union Pacific's huge Bailey Yard, where the railroad assembles freight trains. Berndt said none carried hazardous materials.

Downed power lines and other debris closed several roads in the area, making travel dangerous, and crews headed out on Monday to survey the damage, Berndt said.

Record-breaking high temperatures east of the Rocky Mountains for the past several days will gradually give way to cooler temperatures, but not before a slow-moving storm makes its way through the southern plains, AccuWeather meteorologist Tom Kines said.

"The storm has got some punch to it. There's definitely the concern for severe weather" in Texas, Oklahoma and Arkansas, he said. The risk for tornadoes on Monday and Tuesday was anywhere between Austin, Texas, and Oklahoma City, Oklahoma, he said.

The storm is moving slowly north and east, and could stall out and cause flooding, Kines added.

(Reporting By Andrew Stern; Editing by Greg McCune)