The crush of fans at the Travis Scott concert in Houston initially killed eight people more than a week ago, but the death toll keeps rising.

Mayor Sylvester Turner announced Sunday that Ezra Blount, a 9-year-old boy who was trampled by the crowd, died from extensive injuries, making him the 10th and youngest victim. Blount’s father had tried to save the boy by hoisting him on his shoulders, but lost conciousness as the crowd pressed against him.

If you attended the Astroworld Festival and shot video, you can help us investigate what went wrong and why.

The Houston Chronicle set up a web form where fans can submit videos they shot at the chaotic concert. The timestamps and locations of the videos can help a team of reporters construct a timeline of what happened. Timestamps were incredibly useful for my colleagues Zach Despart and Dug Begley when we wrote this initial account of the mayhem:

At 9:11 p.m., concertgoer Eric Daniels, 47, began taking video of attendees trying to escape the section closest to the stage. Timestamps from the videos he and others took reveal a chronology of the mounting chaos.

At 9:23 p.m., concertgoer Ellen Elise Evans filmed fans climbing speaker rigging to escape the crush. Unable to move in the throng, she described those moments as the scariest in her life.

“People were getting pushed down or around. It was a tidal wave of human bodies,” Evans said. “I saw girls crying and wanting to leave.”

At 9:24 p.m., as Scott noticed a man who had a climbed a tree for a better view, fans to the left of the stage were screaming for a medic and waving their hands to get his attention. Scott launched into his song “No Bystanders.”

At 9:28 p.m., Daniels filmed staff performing chest compressions on an unresponsive man in the crowd.

“It was devastating because we saw people who were oblivious, enjoying the concert and celebrating, while right next to them, there’s somebody on the ground fighting for their life,” said Daniels, who attended the show with his 18-year-old son.

You can help us piece together this tragedy with video you took as a witness. Or, if you’re a first responder or concert promoter with information or documents that can shed light on what went wrong, here’s every conceivable way to get in touch with us.