Tornadoes tear through Kansas, Oklahoma; Colorado cleans upStory Highlights
NEW: Two victims of Friday night tornadoes found dead in Kansas
Tornadoes sweep across northern Oklahoma
Multiple twisters struck Kansas on Friday
Colorado residents begin returning to tornado-damaged homes
(CNN) -- Tornadoes formed Saturday over northern Oklahoma, skipping across the rural landscape and vaporizing a hog farm about an hour northwest of Oklahoma City, officials said.
Tornadoes formed over northern Oklahoma on Saturday in the state's third day of severe weather.
more photos » First, shingles skittered off the roof, and then the roof itself peeled away like the top of a sardine can and filled the air with debris, video showed.
Manager Joe Popplewell was with his family in a storm shelter at his home a few miles away when the tornado passed overhead.
"As it was coming towards our home, it kind of lifted up, lost its organization a bit," said Popplewell's wife, Susie. "When it came down, it wasn't as big."
As the eye of the tornado drilled a path through the farm, trees were torn from the ground, their limbs launched hundreds of feet aloft.
After the storm passed, Popplewell rushed to the farm, expecting the worst.
"Fortunately, there were no injuries at all to any of the people as they were working at the farm," he said, referring to the 4,000-sow facility.
"At this point, we don't believe that, amazingly, that any animals were injured. I can't believe it," Popplewell said.
The sows were kept in crates, which served as shields against the wind, he said. The biggest challenge now is to find a safe place to hold the animals where they'll have access to food and water, according to Popplewell.
Area hospitals said they had received no immediate reports of injury as police tried to keep motorists from the affected areas.
"They're trying to block off the highway," Hennessey Police Department dispatcher Jana Butts said, referring to U.S. 81 between Hennessey and Bison. Watch the tornadoes tear through Oklahoma »
Jerry Niles, undersheriff for the Garfield County Sheriff's Office, watched from his car as a tornado formed near him. "
I'm backing up and getting out of the way," he said. "We don't need to be near a funnel of that size."
He said that about half of the area's homes have cellars and urged residents to listen to weather radios.
The twisters touched down during the third consecutive day of severe weather in Oklahoma.
A tornado touched down Friday night in Harper County, damaging power lines and bringing a sudden halt to a high school graduation, KMTV reported.
The storms gathered intensity as they traveled into Kansas, where they turned fatal.
Two people were found dead east of Pratt in south central Kansas on Saturday in a car accident caused by a tornado, the Pratt County Sheriff's Office said.
Forecasters said Saturday that at least a dozen tornadoes spun across western and central Kansas a day earlier, destroying numerous homes, downing trees and injuring several people. Tornado activity up in 2008 »
The National Weather Service in Dodge City said that at least 10 twisters touched down in central Kansas, and the Goodland office reported seven or eight in the western part of the state.
At least four people were hurt in Stafford County, including one person who was taken to a Wichita hospital with serious injuries, said Sharon Watson, spokeswoman for the Kansas Adjutant General's Department.
Meanwhile in Colorado, where a large tornado devastated the northern farm town of Windsor, residents were expected to return to their homes in an area of town that officials had deemed unsafe after Thursday's twister. Watch how day-care workers protected children »
Natural gas leaks and the threat of explosions had kept hundreds of residents from their homes Friday.
Officials were meeting with residents to plan their return, incident management team spokesman Dan Hatlestad said.
"With no power, it may be an unpleasant place to live, but it's up to the homeowners," Hatlestad said.
The tornado, with wind speeds between 111 mph and 165 mph, tore through a 35-mile stretch of northern Colorado, killing one person and injuring dozens. It tipped 15 rail cars off the tracks in Windsor, about 70 miles north of Denver.
In Kansas, the weather service sent out survey teams Saturday morning to determine the size of the twisters. Ed Berry, science operations officer in the Dodge City office, said many of the twisters appear to be significant in size.
In Stafford County, at least seven homes suffered major damage, along with damage to several other structures, power lines and trees, Watson said Saturday.
A man in Gove County received minor injuries after his car was blown across Interstate 70 into a ditch, according to George Lies, emergency management director for Logan and Gove Counties.
Lies said two tornadoes hit in Gove County, with at least a dozen homes sustaining major damage.
One twister was on the ground south of Quinter, went back into the clouds as it passed over the town and then dropped back down on the other side, damaging four rural houses.
Portions of Kansas also have been hit hard by flooding, with as much as 8 inches of rain falling in a 48-hour period, according to Chris Foltz, meteorologist for the National Weather Service in Goodland.
