More than 80 people have been killed by tornadoes that have hit six American states, AFP reported on Sunday. Kentucky is the worst-affected state.

More than 70 people are believed to be dead in Kentucky alone, while at least six were killed in Illinois. Seven others were killed in others states, including Arkansas, Tennessee and Missouri, bringing the toll to 83.

Over 30 tornadoes have been reported in the six states, according to CNN. A stretch of more than 250 miles, or 402.33 km, from Arkansas to Kentucky might have been hit by one long-track tornado, according to CNN meteorologists.

Kentucky Governor Andy Beshear said that the toll in the state could rise to over 100 after a tornado touched down in his state and affected 10 or more counties, reported AP.

“This event is the worst, most devastating, most deadly tornado event in Kentucky’s history,” Beshear said. “The devastation is unlike anything I have seen in my life, and I have trouble putting it into words.”

Most of the fatalities were reported in the state from a candle factory in Mayfield town where 110 people were working. The roof of the factory collapsed, leading to several deaths.

“They rescued 40 [from the factory],” Beshear said. “There’s at least 15 feet of metal with cars on top of it, barrels of corrosive chemicals that are there, it will be a miracle if anybody else is found alive in it.”

Kyanna Parsons-Perez, a survivor of the incident, said workers had been taken to a safety area before the storm hit. While attendance was being taken there, she saw “a little dust of wind”.

“My ears start popping,” Parsons-Perez told CNN. “And it was like the building, we all just rocked back and forth, and then boom – everything fell on us.”

Beshear has declared a state of emergency.

One of the tornadoes hit an Amazon warehouse in Illinois’ city of Edwardsville, in which about 100 workers are believed to have been trapped inside.

“We identified 45 personnel who made it out of the building safely, one who had to be airlifted to a regional hospital for treatment, and six fatalities,” Edwardsville fire chief James Whiteford told reporters.

He added that the focus of the operation has now turned from rescue to “recovery,” fuelling fears that the toll could rise.

In Missouri, the office of Governor Mike Parson said the tornadoes killed at least two people and that the initial assessments suggest major damage was done to hundreds of homes and buildings.

Workers at a National Weather Service office in the state had to take shelter as a tornado passed near their office in Weldon Spring.

“This was an incredible storm that lasted a long time and covered a lot of territory,” said Larry Vannozzi, meteorologist in charge of the weather service office.

‘Likely the largest tornado outbreak’ in US: Joe Biden

US President Joe Biden said that it is likely to be one of the largest tornado outbreaks in the country’s history.

“They [the residents] lost their homes,” Biden said in an address to the country. “They lost their businesses. And it’s a tragedy. It’s a tragedy. And we still don’t know how many lives were lost or the full extent of the damage.”

Biden stressed that this administration will do everything to help.

“I’ve spoken several times today with the head of FEMA [Federal Emergency Management Agency] as well as the director of FEMA, who’s already deployed emergency response personnel to these states, search-and-rescue teams, water and other supplies,” the president said, adding members of the emergency management agency were on the ground to assess damages.

Biden said that he has approved the request for emergency declaration made by the Kentucky governor that will “accelerate federal emergency assistance” for the state.

“And I stand ready to do the same for the governors of the other states – and I’ve made it clear to them – if they request emergency declaration,” he added.