Two people were shot to death and another was wounded earlier this week as a viral social media stunt called “The Milk Crate Challenge” was being filmed outside a school in Shreveport, Louisiana, according to several news reports.

The drive-by shooting happened about 5:30 p.m. Sunday outside the Linwood Public Charter School on West 70th Street, where a group of friends was attempting the feat of walking over a pyramid of plastic milk crates without toppling over, Newsweek reported.

As one of the men successfully reached the top of the structure, gunfire rang out.

At least 21 or more rounds could be heard in rapid fire on a video filmed by one of the bystanders. That person quickly took cover behind a car while yelling “Get me my gun, get me my gun!”

It was unclear whether the individuals involved in the crate challenge were the intended targets of the shooting. Authorities have not yet revealed any suspects in the case.

Video of the moment the incident happened emerged the same day on Twitter.

More than two dozen evidence markers peppered the street where the bullet casings fell during the shooting, according to KSLA News 12, which clarified that only two had died when multiple earlier reports indicated three were dead.

The Shreveport Police Department told KSLA that a woman was found dead at a nearby convenience store in the back seat of a car. Another man also died on the scene, while a third male victim was shot and wounded.

The dead woman was later identified as 19-year-old Paris King, but the person driving the car she was in and another passenger were not injured, KSLA reported.

Fingerprints confirmed the identity of the second dead victim as 34-year-old Lazarus Thomas, KSLA reported. Officials did not indicate whether he was among the men performing the daring crate stunt outside the school.

Videos of people performing the challenge took off on social media this past week. The dangerous stunt has typically ended in serious injuries because the lightweight pyramid falls apart like a house of cards if one is either too heavy or doesn’t walk across the makeshift staircase fast enough.

The shooting remains under investigation.