A major storm system ripped through multiple U.S. states on Friday, hitting a candle factory in Kentucky with more than 100 employees still inside the building at the time a tornado struck.

The series of U.S. storms started early on Friday and are already blamed for multiple deaths and injuries across parts of the Midwest and South.

Kentucky Gov. Andy Beshear said at a news conference that it is going to be "some of the worst tornado damage that we've seen for a long time," calling the weather event a "mass casualty" incident.

"We believe our death toll from this event will exceed 50 Kentuckians, probably end up closer to 70 to 100 lost lives," Beshear said.

 "There were about 110 people in [the factory] at the time that the tornado hit it," he added.

Beshear also announced the deployment of about 180 guardsmen, including search and extraction, as the governor declared a state of emergency and requested President Joe Biden a federal emergency declaration.

Kentucky emergency management director Michael Dossett said at the same briefing that the storm appears to be the first quad-state tornado storm in the state's history.

"This tornado event may surpass the one in 1974 … as one of the most deadliest in Kentucky's history," Dossett said, adding that this will be "one of the darkest days in the state's history."

The primary tornado was on the ground for 200-miles, Beshear said and would be the longest traveled of any tornado in the state for nearly 100 years.