City officials have said that the claim that those in the video were caught unaware by the raising bridge is “not credible,” according to the Chicago Tribune.

While officials didn’t clarify why they think the people in the video couldn’t have been accidentally trapped on the bridge when it was raised, the bridges often have alarms go off nearby before they raise and lower. They also raise and lower very slowly, giving people ample time to leave them before they raise or lower completely.

Michael Claffey, a representative of the Chicago Department of Transportation, speaking to the Tribune, called the video “extremely reckless and potentially deadly behavior” and said that Chicago police are investigating the people involved for possible trespassing.

Video of the individuals was reportedly posted on Monday by a Hyde Park resident named Dylan Brandon, who claimed to have found it on Twitter. Brandon said he didn’t know the people in the video. City officials only became aware of the video as it began circulating online.

Chicago Police spokesperson Maggie Huynh said the downtown bridges were raised each night from August 10 to August 16. The bridges were raised in response to a civil uprising that occurred on Sunday, August 9.

According to the investigative journalism nonprofit site ProPublica, on Sunday evening, angry Chicagoans began gathered in the city’s downtown area after police in the south side neighborhood of Englewood shot a 20-year-old man who they claimed had first shot at them.

As Sunday night stretched into Monday’s early morning hours, citizens began ransacking stores along Michigan Avenue. The unrest was met by 400 police officers—13 officers were injured and more than 100 people were arrested.

On Monday morning, Lightfoot called the uprising an act of “brazen and extensive criminal looting and destruction” and disavowed the uprising’s possible connection to the shooting. She pledged to restrict downtown access for the next few nights by discontinuing public train service, closing expressway ramps and limiting access to five other city spots—she also began raising the bridges.

The publication noted that locals can’t recall any time in the city’s past when the bridges were raised to stop crime, and accused Lightfoot of literally dividing the city’s residents instead of addressing the underlying inequalities causing unrest, something Lightfoot pledged to do as a mayoral candidate.

Newsweek contacted Lightfoot’s office for comment.