More than 80 people in Kentucky were killed after tornadoes ripped across several U.S. states late Friday.

“I know we’ve lost more than 80 Kentuckians. That number is going to exceed more than 100. This is the deadliest tornado event we’ve ever had,” Governor Andy Beshear said on CNN Sunday morning.

Arkansas, Illinois, Kentucky, Missouri, Mississippi and Tennessee were struck by a series of dangerous storms and tornadoes on Friday night. Beshear declared a state of emergency, and President Joe Biden said that FEMA, the Federal Emergency Management Agency, is on the ground in each of the six states to assess the damages.

Beshear will hold a press conference on the latest developments at 4-15 p.m. ET.

There are 12 confirmed fatalities from Friday’s storm in Warren County, Kentucky, where more than 500 homes and 100 businesses were destroyed. At least 12 fatalities were reported in the Bremen community area of Muhlenberg County, NBC News reported.

In Illinois, six people were confirmed dead and one injured after an Amazon distribution center collapsed in Edwardsville. A total of 45 people were rescued safely from the site, and the operation has moved from a rescue to a recovery mission, Governor J. B. Pritzker said in a press conference Saturday.

“The federal government will do everything, everything it can possibly do to help,” Biden said during a press conference Saturday from Wilmington, Delaware.

“I promise you, whatever is needed, whatever is needed, the federal government is going to find a way to supply it,” Biden added.

One of the storms ripped through four states, Arkansas, Missouri, Tennessee and Kentucky, on at least a 220-mile path. The trail puts it among the longest tornadoes in U.S. history if it remained on the ground. The National Weather Service is set to perform an official survey to determine if it was a single, continuous tornado, NBC News reported.

—CNBC’s Jessica Bursztynsky contributed to this report.