Rescue workers across the middle of the US resumed their search efforts on Sunday, desperately trying to find survivors in the wreckage after a flurry of tornadoes ripped through at least six states on Friday night, killing at least 90 people.

Officials warned that the toll, which included at least 80 in Kentucky alone, was almost certain to rise as they sifted through the ruins.

The tornadoes tore through states, including Arkansas, Illinois, Kentucky, Mississippi, Missouri and Tennessee, said Bill Bunting, the operations chief at the Storm Prediction Centre, part of the National Weather Service.

The tornado outbreak killed people who were working the Friday night shifts at a candle factory in Kentucky, where scores are believed to have died, and at an Amazon warehouse in Illinois, where at least six people were killed and where recovery operations were continuing on Sunday.

In a speech on Saturday afternoon in Delaware, where he was spending the weekend, President Joe Biden said his administration would do “everything it can possibly do to help” the states that had sustained serious damage in the tornado outbreak.

“This is likely to be one of the largest tornado outbreaks in our history,” he said, adding that he had approved the emergency declaration that was requested by governor Andy Beshear of Kentucky.

In remarks to the media on Saturday after touring some of the hardest-hit places, Beshear paused at times, unable to describe the sheer scale of damage. “The level of devastation is unlike anything I have ever seen,” he said. He called it the most devastating tornado event in Kentucky history.

While the destruction was spread throughout western Kentucky, much of the estimated death toll came from a single building, the Mayfield Consumer Products candle factory, just southwest of the small city of Mayfield. Officials described an almost unfathomable level of destruction there, a knot of concrete and metal strewn with cars and 55-gallon drums leaking corrosive fluids into the wreckage.

Appearing on CNN’s “State of the Union” on Sunday morning, Beshear said it would be “a miracle” to find anyone still alive in the factory. He added that across the state, many people were still missing, though he did not specify how many.

In Tennessee, at least four people were confirmed dead, with the worst damage reported in the northwestern corner of the state. In Arkansas, one person died at a Dollar General store in Leachville, and a 94-year-old man was killed when the tornado slammed into a nursing home in the city of Monette.

In Missouri, at least one person died and two others were injured when a tornado slammed down in the community of Defiance.

This baby is alive because the parents put her car seat moments before the Tornado struck. Twitter/@SequoyahKTUL8

Officials in Edwardsville, Ill, a small city across the Mississippi River from St Louis, said at least six people had been killed at an Amazon warehouse when a direct hit from a tornado around 8.30 on Friday night caused two of the building’s 40-foot-high concrete walls to collapse.

“We don’t expect that anyone could be surviving,” said James Whiteford, the chief of the Edwardsville Fire Department. The chief said that the tornado had come at the time of a shift change and that it was unclear how many people would have been in the building.

New York Times News Service