Director Kaythryn Bigelow‘s (The Hurt LockerZero Dark Thirty) upcoming film Detroit is based on a true tragedy that occurred in a Detroit motel during the Detroit Riots of 1967, one of the deadliest police/civilian clashes in American history.

While the riot began after police raided an unlicensed bar in on 12th street in Detroit, Michigan, on July 23, 1967, the Algiers Motel incident happened two days later, during the second day of the riot.

With multiple law enforcement agencies called into the area to quell the riot, several units of various agencies were posted around the Algiers Motel. After it was reported that shots had been fired around the hotel, Detroit policemen and State Troopers descended on the building to investigate.

But rather than look for answers, the law enforcement officials went in firing. The task force ran into a group of teenagers listening to music and immediately assumed that they were criminals. During the night, three black teenage males were killed, two white females and seven black males were seriously injured.

The task force did not properly report the murders and one of the deaths remains unexplained to this day. While members of the task force were charged with assault, conspiracy, murder and conspiracy to commit civil rights abuses, not a single law enforcement officer was found guilty.

“I thought, ‘Am I the perfect person to tell this story? No,'” Bigelow told Variety. “However, I’m able to tell this story, and it’s been 50 years since it’s been told.”

She continued, “With the events unfolding today, the story needed to see the light of day. My hope is that a dialogue comes out of this film that can begin to humanize a situation that often feels very abstract.”

Bigelow’s film, based on the incident, stars John BoyegaWill PoulterAlgee SmithJason MitchellJohn Krasinski and Anthony Mackie.

Detroit will be released nationwide on August 4. Watch the trailer below.