Originally Published: 19 APR 23 21:21 ET

Updated: 20 APR 23 10:19 ET

By Jennifer Gray, Aya Elamroussi, Robert Shackleford and Tina Burnside, CNN

(CNN) -- More severe storms are threatening some 50 million people from Texas to Wisconsin after the same system left at least two people dead in Oklahoma, with a dozen tornadoes reported across three states and search-and-rescue still underway in some places.

The toll of fatalities and injuries in Cole could climb as damage assessments continue, Deputy Scott Gibbons with the McClain County Sheriff's Office told CNN. First responders have gotten reports of people trapped in shelters, and teams are searching systematically across a 10-miles path must navigate roads littered with downed power lines and debris, he added.

The same system that spawned Wednesday's severe storms is heading east Thursday, with rain, hail, damaging winds and some tornadoes and flash flooding possible. Areas from the hill country of Texas to southern Illinois -- including Dallas and Houston, plus Little Rock, Arkansas, and Shreveport, Louisiana -- face a Level 2 out of 5 "slight risk" of severe weather, the Storm Prediction Center said.

Wednesday's storms were reported across Oklahoma, Kansas and Iowa, with Oklahoma appearing to be the hardest hit. About 16,000 homes and businesses in the state were without power Thursday morning.

A reported tornado in Cole, home to more than 600 people about 30 miles south of Oklahoma City, appears to have been one of the most significant. To resident Barry Harbison, it felt like a roller-coaster when the storm lifted his trailer home off the ground and tossed it -- while he was stuck in it, he said.

"I stayed in the bathroom and (the storm) picked up the whole trailer and moved it," Harbison told CNN affiliate KOCO.

The National Weather Service in Norman, Oklahoma, plans to survey Cole, Shawnee and the Etowah-Pink-Stella area Thursday. In addition to nine reports of tornadoes in Oklahoma, four tornado reports were recorded in Iowa and three in Kansas on Wednesday; of those, two tornadoes in Iowa and one in Kansas have been preliminarily confirmed.

'Blessed everybody is alive'

About 60 miles east of Cole, a large and very dangerous tornado was reported in Shawnee, a city of about 30,000 people in Pottawatomie County. The storm was moving erratically north of the city around 10 p.m. Wednesday, the National Weather Service in Norman said.

Shawnee Public Schools canceled classes Thursday, the district announced on Facebook.

More than 30 residents at Brookdale Senior Living, an assisted living facility in Shawnee, Oklahoma, were evacuated after the building's windows were blown out and water seeped inside, according to Shelee Stewart, the executive director.

"We've been blessed everybody is alive," Stewart told KOCO, noting there were no major injuries.

Stewart described the staff who helped guide residents to the bathrooms while the storm passed as "heroes," adding some had minor scratches.

As crews spread out in the county to respond to the storms, the Pottawatomie County emergency management agency warned residents not to leave their homes to observe the damage, noting that hinders response efforts.

"There is tremendous amounts of ponding on areas storms have come through so please do not drive through the water!" the agency said.

"Our county was hit hard and it will take a while for every area to be checked," the agency later said.

"If you can, check on your neighbors, but be mindful of potential gas leaks and possibly downed power lines," Shawnee Police said Wednesday evening in a Facebook post.

Oklahoma Baptist University in Shawnee also canceled classes Thursday and Friday after urging students to avoid being outdoors. No injuries were reported, but the campus was significantly damaged, the university said.

"Authorities are advising students to stay in their housing units through the night," due to downed power lines and scattered debris, the school said.

More severe storms expected Thursday

The main threats from Thursday's severe weather will be large hail and strong winds -- and tornadoes can't be ruled out.

"The areas of most concern are eastern North Texas (including the DFW Metro) and much of Central Texas, though areas east of I-35 will see the higher likelihood for severe storms," said the National Weather Service in Fort Worth.

Heavy rainfall could lead to flash flooding in some locations. Most areas will see 1 to 3 inches of rain, with more in isolated spots.

There is also a much broader Level 1 out of 5 "marginal risk" of storms Thursday from South Texas to the Midwest. This includes places like Chicago, Memphis, Tennessee, and Corpus Christi, Texas.

These areas could also see strong winds, damaging hail and an isolated tornado