- NEW: A "confirmed large and extremely dangerous tornado" strikes Kansas
- The tornado is moving toward Wichita, Kansas
- A possible tornado hits hospital in Iowa; no serious injuries reported
- Kansas and Missouri forecasters are testing graphic warnings
Read more about this story at CNN affiliate KSNW. Are you there? Share videos, pictures and stories.
(CNN) -- Suspected tornadoes cut a path across the Midwest, sending tens of thousands running for shelter late Saturday in Kansas as they barreled down on Wichita, Salina and El Dorado.
The outbreak predicted by forecasters, who said there was a "high risk" of severe thunderstorms into Sunday in portions of Nebraska, Iowa, Kansas and Oklahoma, put more than 5 million people on alert.
In one of its strongest warnings, the National Weather Service warned that major damage to houses and buildings were likely, "and complete destruction was possible."
Severe weather tracker 
Severe weather 101 By 11 p.m. (12 a.m. ET), CNN affiliate KSNW reported a roof collapse at Spirit Aerosystems from the storm. The affiliate also said there are reports of hangar damage at a local airport and military base.
More than 20,000 customers were reported in the dark and the local 911 call center was also experiencing some problems since it was directly in the path of the storm. The affiliate said flooding is taking place in many places and that a trailer park was also hard hit by the reported tornado.
Earlier, a tornado struck a hospital in Creston, Iowa. A search-and-rescue operation was under way.
CNN's Rob Marciano reported from Oklahoma and Kansas. CNN's Jacqui Jeras, Nick Valencia and Greg Morrison reported from Atlanta.
