Deaths confirmed in collapsed Amazon warehouse in Illinois after severe weather

Police confirmed there were fatalities at an Amazon warehouse in Edwardsville, Illinois, after severe weather caused what police said was "catastrophic damage" to the building.

This footage shows an on-the-ground view of the scene where KSDK said a roof and a wall close to the length of a football field collapsed.

RELATED: Tornadoes bring death, injuries, damage to several states

The Amazon collapse – just across the Mississippi River from St. Louis – was being called a "mass casualty incident" by local emergency responders, but specific details weren’t immediately reported, according to The Associated Press.

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As many as 50 to 100 employees were believed to be inside the building, FOX 2 of St. Louis reported.

The National Weather Service said a radar-confirmed tornado was east of Edwardsville on Friday.

RELATED: WATCH: Terrifying video shows massive tornado sweeping through Kentucky

Thunderstorms started erupting Friday after sunset and triggered numerous tornado warnings across at least seven states, FOX Weather reported. Meteorologists from National Weather Services offices will survey damage paths on Saturday, but initial reports from the Storm Prediction Center indicate more than two dozen tornadoes impacted states from Arkansas to Kentucky.

President Joe Biden tweeted Saturday that he was briefed on the situation and pledged the affected states would "have what they need as the search for survivors and damage assessments continue."