It is believed that at least seven of the 10 people who died at or following Astroworld Festival this month were in the same small, enclosed area of the crowd.

The Washington Post reports that its investigation, which utilized videos of the disaster and interviews with witnesses, deduced that the crowd surge hit one area of the crowd the worst. Most of the attendees of the festival who perished were situated in the south quadrant, where they were enclosed on three sides by metal barriers. Witnesses said they saw people collapse during the crush due to the pressure, and according to analysis by crowd experts at Carnegie Mellon University there was only 1.85 square feet of space for each person.

Analysis of video footage shows that the main stage, where Travis Scott was set to perform at 9 p.m., began to fill up three hours before any performances took place there. For reference, all the other artists at the festival performed at a second stage, and at approximately 8:30 p.m. fans could be seen rushing from SZA’s performance to the stage Scott would step foot on. The crowd was already tightly packed before the influx of people, which caught some concertgoers in the current. Crowd experts believe the rush resulted in individuals getting compressed by the pressure.

“In general, that’s not a safe design because you can’t regulate the number of people who are in a high-pressure area,” said University of Suffolk visiting professor Keith Still, who criticized the rigid barriers.

Video footage analyzed showed some of the victims, including 23-year-old Rodolfo Peña, fighting to get more space amid the crowd. A clip from just 16 minutes into the concert shows multiple unconscious people lying in a pile in the south quadrant, including 21-year-old Axel Acosta, 21-year-old Jacob Jurinek, and 21-year-old Franco Patino.

“People were literally on the floor getting their faces stomped in. … We were just trying to pull kids over that barricade,” said witness Bill Nasser, who tried to help by moving injured people to the passageway for concert staff. The concert lasted for about 72 minutes, and continued for over 40 minutes after police reported multiple casualties.

A criminal investigation into the disaster is ongoing. In addition to the 10 deaths, over 300 concertgoers were injured at the festival and 25 were hospitalized. A variety of lawsuits have already been filed.