A series of tornadoes, including a major twister, touched down southwest of Oklahoma City, flipping cars and causing severe flooding and the escape of bears from an exotic wildlife park, officials said.
There were no immediate reports of injuries, but several reports of damaged structures, as a storm system brought severe weather to several Great Plains states, officials said.
Bears briefly escaped from enclosures at an animal park after a tornado struck the city of Tuttle, about 50km southwest of Oklahoma City, the Grady County Sheriff's Office said. Officials earlier said tigers had escaped.
Earlier in the day, passengers, visitors and employees at the Will Rogers World Airport in Oklahoma City were evacuated to a pedestrian tunnel for about 30 minutes as the storms moved through the area, the airport said.
The tornadoes flipped cars, downed power lines and snapped trees. Several roads were closed because of debris, the Oklahoma Department of Emergency Management said.
The National Weather Service issued a flash flood emergency for downtown Oklahoma City amid storms and heavy rain in the broader area. It said the airport received 17.5cm of rain for the day.
Severe flooding was reported in the downtown Oklahoma City business district and South Oklahoma City, where local media reported a possible drowning victim after a flash flood.
Grady County officials said 10 homes in the nearby town of Amber were damaged along with 25 homes in Bridge Creek. South Oklahoma City reported a hotel along Interstate 35 was among other structures damaged.
Fire crews were responding to flood-related incidents such as submerged cars in Oklahoma City after the metropolitan area was hit with more than 20cm of rain in the last 24 hours.
In neighboring Del City, officials said they were beginning boat rescues in flooded neighbourhoods.
The Oklahoma Corporation Commission said more than 10,000 homes and businesses were without power statewide.
The National Weather Service has issued a tornado watch for an area stretching from central Texas to central Nebraska.
There had been about two dozen tornadoes reported in the area, it said.
The Oklahoma City suburb of Moore was placed under a tornado emergency. Moore was devastated by a tornado about two years ago that killed 24 and injured more than 300.
