Police in Edwardsville, Illinois, on Saturday confirmed there were at least six fatalities after a tornado caused a portion of an Amazon warehouse to collapse.

The Collinsville Emergency Management Agency described the scene as a "mass casualty incident."

Reuters reported 45 people made it out safely.

At a press conference on Saturday, Edwardsville Police Chief Mike Fillback said it is still unclear how many people were at the Amazon facility. The number could be about 100.

“The safety and well-being of our employees and partners is our top priority right now,” Amazon spokesperson Richard Rocha said in a statement. “We’re assessing the situation and will share additional information when it’s available.”

The St. Louis Post-Dispatch reported that rescue crews continue to sort through the rubble to determine if there are more people trapped inside.

“My prayers are with the people of Edwardsville tonight,” Illinois Gov. J.B. Pritzker said in a tweet. “I've reached out to the mayor to provide any needed state resources."

The St. Louis area and other parts of the Midwest and South were hit by powerful storms and tornadoes on Friday. At least five states reported severe damage from more than 30 tornadoes.

Kentucky officials said at least 70 people have been killed and the state’s death toll could exceed 100. Gov. Andy Beshear described the devastation as "unlike anything I have ever seen."