(CNN) -- At least two tornadoes touched down in Oklahoma Tuesday, with one causing an unspecific number of deaths and the other marching toward Oklahoma City, officials said.
Canadian County Sheriff Randall Edwards told CNN a storm that crossed I-40 near El Reno claimed lives, destroyed homes and caused a gas leak at an energy plant.
The twister injured motorists on Interstate 40 and U.S. 81, Smith said. Deputies were attending to the injured, and there were reports of property damage in the area.
County Emergency Management Director Jerry Smith told CNN the storm moved past Calumet and Edmond, north of the capital.
Another tornado was seen at Chickasha, about 40 miles southwest of Oklahoma City.
The National Weather Service warned residents and I-44 drivers to take precautionary action.
This and another tornadic thunderstorm south of Chickasha were moving toward the northeast at 35 miles per hour and will move into populated areas of the Oklahoma City area, including Moore and Norman, in the next hour.
"This is an extremely dangerous and life-threatening situation," the National Weather Service said.
Tornado warnings were issued in Oklahoma County, Canadian County and Grady County, indicating other twisters had touched down.
CNN Oklahoma City officials broadcast images of the large storm, dumping rain as it moved toward more populated areas.
More twisters and severe thunderstorms are expected to push through the region and threaten Joplin, Missouri, which was devastated by a tornado on Sunday.
The National Weather Service reported the possible twister touched down near Hinton, west of Oklahoma City, near the communities of Sickles and Lookeba.
Tornado watches were in effect Tuesday afternoon in Texas, Oklahoma and Kansas.
In anticipation of the severe weather, American Airlines canceled 126 arriving and departing flights at Dallas-Fort Worth International Airport, spokesman Ed Martelle told CNN.
Operations were suspended late Tuesday afternoon at Will Rogers World Airport in Oklahoma City.
A "particularly dangerous situation" tornado watch was issued for a large part of Oklahoma and northern Texas until 10 p.m. CT. This includes Oklahoma City and portions of the Dallas/Fort Worth metro area, according to CNN meteorologist Dave Hennen.
The National Weather Service's Storm Prediction Center said the high-risk area for severe storms includes southern Kansas, most of Oklahoma and southward into Texas.
Surrounding the high-risk area is a large "moderate"-risk area where tornadoes are possible. This includes the cities of Dallas; Kansas City, Missouri; Springfield, Missouri; and Joplin.
The worst for Joplin is expected to be between 8 p.m. and midnight. Tornadoes, large hail and damaging winds are possible, according to Hennen.
The tornado threat will slowly diminish late Tuesday evening and overnight, but isolated tornadoes, large hail and damaging straight-line (non-tornado-type) winds will continue.
The tornado that struck Joplin on Sunday killed at least 118 people, authorities said Tuesday, making it the deadliest single U.S. tornado since modern record-keeping began more than 60 years ago.
Source http://edition.cnn.com/2011/US/05/24/severe.weather/index.html?hpt=T1&iref=BN1
