A huge storm system covering states in the US Midwest and South on Friday produced a series of powerful tornadoes that caused massive damage and left casualties in multiple locations, including three deaths in Arkansas and one death in Illinois.

The storm stretched from Iowa to Indiana in the north and from Texas to Georgia in the South as the National Oceanic and Atmospheric Administration (NOAA) Storm Prediction Center issued a rare “high risk” severe weather forecast through Friday evening.

Numerous tornadoes were spotted in Iowa, Illinois, Arkansas and Tennessee. Meteorologists report that as many as 89 million people in at least 15 states were at risk from the “explosive” storms.

The most severe damage has so far been reported in Little Rock, Arkansas, where an exceptionally large tornado carved a path through the metro area.

As of this writing, one person is confirmed dead and at least 24 people had been hospitalized in Little Rock as the tornado tore down trees, ripped roofs off buildings and destroyed homes. The New York Times reported that five people were in critical condition at two Baptist Health medical centers in the area and that the hospitals were “anticipating a surge of additional patients.”

The path of destruction in Little Rock has been described by local news media as “catastrophic,” as search and rescue teams began to comb through the wreckage for people trapped or injured. The roof of a Kroger grocery store was ripped off with a number of shoppers still inside.

A state of emergency has been declared by the Arkansas Governor Sarah Huckabee Sanders and she has activated the National Guard.

The staff at the National Weather Service office in Little Rock was forced to move into a tornado shelter on Friday afternoon, when the facility was determined to be in the tornado’s path. The Memphis office of the weather service was standing in for the team and subsequently issued a second tornado warning for the Little Rock area.

Officials from Wynne, Arkansas—a town of 8,300 people approximately 100 miles to the east of Little Rock—are reporting that there is “total destruction throughout the town,” and that dozens of people are trapped in the wreckage left behind by a second tornado. Two people were killed by the storm in Wynn, according to Arkansas emergency manager, Rebekah Magnus.

Major destruction is also being reported in eastern Iowa. Multiple homes were destroyed in Hills, Iowa, about 8 miles south of Iowa City, on Friday with reports that hundreds of people were helping their neighbors who were hit by a tornado.

Video was posted on social media of a large tornado touching down in Sigourney, Iowa, a town of 2,000 people 70 miles southwest of Cedar Rapids. The New York Times spoke with Manny Galvez, a resident of Coralville near Cedar Rapids, who said he sought shelter in his basement just before 5:00pm and emerged 40 minutes later to find nearby homes destroyed and trucks flipped over.

At 9:00 p.m., CBS News reported that the roof of the Apollo Theater collapsed in Belvedere, Illinois while a music concert was underway. The report said, “Video from the scene showed the marquee collapsed, as did a large portion of the large bowstring truss roof,” and, “Inside the theater, the ceiling in front of the proscenium collapsed – leaving the space open to the outside. People were likely gathered in front of the stage at the time.” Twenty-eight people were injured and one person was killed in the collapse.

According to Poweroutage.us, a website that tracks electricity outages across the US, more than 80,000 people were without power in Arkansas and another 140,000 people were without power in Colorado, Oklahoma, Iowa, Illinois, Missouri and Tennessee.

The destruction of the storm and tornadoes on Friday followed the weather events a week ago in Mississippi which caused widespread damage in several rural communities. Ten tornadoes were confirmed in Mississippi, Alabama and Tennessee within 24 hours by the National Weather Service.

One of the twisters was characterized as an EF4 tornado with wind gusts reaching 170 miles per hour, and two others as EF3 with gusts at 155 miles per hour. As of Friday, a total of 21 people were killed by three tornadoes in Mississippi.

According to a study published in January, there will likely be more killer tornado- and hail-spawning supercells as the world warms. The study entitled, “The Future of Super Cells in the United States,” and published by the Bulletin of the American Meteorological Society also says that lethal storms will edge eastward to strike more frequently in the more populous Southern states.

While no individual storm can be connected directly to global warming, the recent powerful storms and destructive tornadoes fit the more dangerous pattern anticipated by the study, including more nighttime strikes in a southern region with more people, poverty and vulnerable housing than where storms hit in the twentieth century.

The study also says the storm season will start a month earlier than it used to. Among the statistical projections, derived from computer simulations, that the report makes, are that there will be a nationwide 6.6 percent increase in supercells and a 25.8 percent increase in the area and time the strongest supercells twist and tear over land under a scenario of moderate levels of future warming by the end of the century.

The study says that a supercell is a “distinct type of intense, long-lived thunderstorm that is defined by its quasi-steady, rotating updraft. Supercells are responsible for most damaging hail and deadly tornadoes, causing billions of dollars in losses and hundreds of casualties annually.”