Illinois Gov. JB Pritzker announced Saturday that six people were killed at an Amazon warehouse that collapsed Friday night.
"This is a tragic day in Illinois history," Pritzker said.
The warehouse is in Edwardsville, where a tornado touched down around 8:30 Friday night.
Edwardsville Fire Chief James Whiteford said the rescue operation at the warehouse has concluded. He said crews are now focused on recovery efforts.
"Through our efforts so far, we identified 45 personnel who made it out of the building safely," he said. "One who had to be airlifted to a regional hospital for treatment and six fatalities."
Amazon CEO Dave Clark offered condolences to those impacted by the storms.
"We’re continuing to provide support to our employees and partners in the area and across the communities affected by the storms," he said in a tweet. "We also want to thank all of the first responders for their ongoing efforts on the scene."
The severe weather left a trail of damage across the region.
Numerous other states reported tornadoes Friday night and Saturday morning. At least 70 people were killed when a tornado hit the southwestern Kentucky community of Mayfield.
President Joe Biden addressed the nation Saturday. He pledged the federal government's full support to help those affected by the severe weather.