At least two workers were confirmed dead when an Amazon.com warehouse collapsed near St. Louis after tornadoes and strong storms roared through the area late Friday.
Several people remained unaccounted for as rescuers frantically searched for workers who may be trapped in the facility in Edwardsville, Illinois, Police Chief Mike Fillback told reporters. He said about 50 workers were believed to be at the warehouse when it was hit by an extreme "weather-related event" at about 8.30pm on Friday.
At least 30 workers were transported by bus from the scene and others may have left on their own, Mr Fillback said. He said it had been difficult to get an exact number of workers who might be unaccounted for because the warehouse did not have "a set staff."
Amazon CEO Andy Jassy posted on Twitter that the company was "heartbroken over the loss" of its staff members in Edwardsville and would continue to work closely with the local authorities on the rescue efforts.
We've been closely monitoring the terrible situation in Edwardsville, and are heartbroken over the loss of our team members. Our thoughts are with their families at this difficult time. (1/2)
— Andy Jassy (@ajassy) December 11, 2021
Drone footage from the scene showed rescue workers picking through a huge area of debris in the pre-dawn darkness.
One woman outside, Sarah Bierman, said she was very worried about her husband, who works at the warehouse.
"I talked to him about eight o'clock tonight, a little before I texted him, and he was returning to the warehouse to drop his van off," she told a reporter.
"And I haven't heard from him since, I just heard through the news and we live in Edwardsville; we lost power. So I decided to come down here to see what was going on, and I had no idea the building looked that bad. And I'm just; I'm worried sick."

An Amazon spokesperson said the company was working with first responders at the scene.
"We're deeply saddened by the news that members of our Amazon family passed away as a result of the storm," said spokesperson Kelly Natel.
"Our thoughts and prayers are with the victims, their loved ones, and everyone impacted by the storm. We also want to thank all the first responders for their ongoing efforts on scene."
Illinois Governor JB Pritzker tweeted: "My prayers are with the people of Edwardsville tonight, and I've reached out to the mayor to provide any needed state resources."
The U.S. National Weather Service had issued tornado warnings on Friday night for areas in several states including Arkansas, Tennessee, Missouri and Illinois.
So far, at least 70 people have died after a tornado ripped through the southeastern US state of Kentucky, its governor told reporters, as storms ravaged large swathes of the country.