The disaster at a heavy metal concert in Belvidere, Ill., was one of several storm-related episodes that killed at least 20 other people as tornadoes tore through the Midwest and South on Friday.
Crypta, a Brazilian death metal band, had just finished a set at an Illinois theater on Friday when the venue made an announcement: The show would be paused for a half-hour because of dangerous weather raging outside.
A few minutes later, the roof caved in.
“Initially, I was confused because it felt like an earthquake, and I was thinking, ‘Why would there be an earthquake right now?’” said Chris Bryant, 39, an audience member at the concert who narrowly escaped injury at the Apollo Theater in Belvidere, Ill.
“As soon as that happened,” he added, “I watched as the entire roof collapsed on everybody, basically right where we were standing.”
At least one person was killed and 40 others were injured after the roof collapsed at the Apollo, the Boone County emergency managing director, Dan Zaccard, told reporters at a news conference on Saturday morning.
It could have been much worse. Shawn Schadle, fire chief in Belvidere, said on Friday that there had been 260 people inside the building; that its front awning had also collapsed; and that emergency workers in the area had dealt with an electrical fire behind the venue, several gas leaks and an elevator rescue around the same time.
“Many, many ambulances,” he told reporters at the scene as flashing red lights from nearby fire trucks bounced off his uniform. “Many, many responders.”
Chief Schadle said that everyone at the venue had been accounted for and that emergency workers were “looking into the stabilization of the building.” The Apollo has hosted a range of musical performances, including vaudeville and mariachi, since the 1920s.
The roof collapse in Belvidere, a city of about 25,000 people that sits less than 90 miles from both Chicago and Milwaukee, was one of several weather-related fatal episodes across the American South and Midwest on Friday.
A deadly storm system spawned ferocious tornadoes that killed at least 20 other people in Arkansas, Alabama, Illinois, Indiana, Mississippi and Tennessee and left at least 30 people injured in the city of Little Rock, Ark., alone.
Belvidere lies in an area that saw strong wind gusts on Friday night, and Illinois was one of several states across the Midwest, Mid-Atlantic and Northeast where residents were under high wind warnings as dawn approached on Saturday. But it was not immediately clear whether a tornado or just bad weather generally had caused the roof collapse. The National Weather Service said only that the Apollo had suffered “possible tornado damage.”
Whatever the cause, the collapse was so unexpected that it left some audience members “standing around dazed, not knowing what to do,” said Mr. Bryant, who works in the information technology sector and lives in nearby Algonquin, Ill.
“I stood there for probably 10 seconds before I realized there were a bunch of people underneath the roof,” he said.
Footage circulating on social media appeared to show concertgoers trying to find people beneath the rubble inside the venue. Mr. Bryant said that he helped to extricate about five people, and that later he told firefighters which victims to prioritize.
“A few minutes later, I saw the guy that I was standing next to during the concert,” he added. “They had a sheet over him.”
The crowd had come to see Crypta and three other metal bands: Revocation, Skeletal Remains and Morbid Angel. They are traveling across the country this spring as part of a tour called “The United States of Terror.”
None of the musicians could be immediately reached for comment after the disaster, but Crypta said on Instagram that all of them were safe.
Morbid Angel, the Florida-based headline act, said in a Facebook post that its members were still sheltering in place at the venue. “Right now our focus is on making sure everyone in the venue tonight is OK and gets home,” the band said.
As for Mr. Bryant, he was still processing what had happened.
“The guy I was standing next to is dead, and I’m sitting at home, comfortable on my couch,” he said by telephone. “So it’s definitely surreal.”
Emily Cochrane contributed reporting.