Illustration by Alex Castro / The Verge

According to a report from the Retail, Wholesale and Department Store Union (RWDSU), Amazon workers thought smoke was coming from the third floor of their warehouse in Alabama. Workers on the third floor were told to clock out, go on voluntary time off, and evacuate, but employees on the other floors were left to continue working as a vapor spread throughout the facility. The smoke was found to be from a malfunctioning compressor.

Workers on the third floor were evacuated around 1:30PM. Workers on the first floor didn't evacuate until after 5PM after seeing a smoke-like substance. They only knew to evacuate as more employees got word of the situation through the Go screens and A to Z app that Amazon uses to communicate with its workers.

“I don’t know what I was breathing in for that long, and I don’t know if it’s still in the air at work today either”

There was a limited police and fire presence when they got outside. Employees were told to go inside as the overnight shift workers arrived at 7PM.

At first, I thought my glasses were smudged, but then the air got thicker, and my co-worker said he thought it was smoke and we should leave. I don't know what I was breathing in for that long, and I don't know if it's still in the air today.

The RWDSU says workers have reported the situation to theOSHA, and are waiting for further investigation. OSHA opened an investigation into the collapse of an Amazon warehouse in Illinois that killed six workers as a tornado ripped through the Midwest.

The RWDSU's claims were false, according to a statement from Amazon. We are thankful no one was hurt and we appreciate the quick actions of the fire department.

The RWDSU and Amazon didn't immediately respond to The Verge's request for comment.

Workers at Amazon's warehouse in Bessemer have been trying to unionize. A large number of workers voted against unionizing in a February election. Amazon was accused of interfering with the election by union organizers, who claimed that the company had access to mailboxes used by workers to cast their votes. The National Labor Relations Board called for a new vote on February 4th of this year, just as the union vote for an Amazon Staten Island, New York warehouse, called JFK8, began. On April 25th, a Staten Island warehouse called LDJ5 will begin voting.

The Amazon warehouse collapse in Illinois has been added to.