What Is a Crowd Surge, and How Can You Stay Safe in One?

People are still reeling after the deaths of at least eight people at the sold-out Astroworld Festival in Houston last Friday night. Many were injured in a crowd surge that overwhelmed event staff and medical personnel.

The victims ranged in age from 14 to 27, and at least 25 people were taken to the hospital after the event.

“What happened at Astroworld Festival was a tragedy,” Houston Mayor Sylvester Turner said in a statement. “An estimated 50,000 people attended the event Friday night, expecting to enjoy a music concert with friends and return home safely. I extend my condolences to the families of the eight people who died.”

Rapper Travis Scott, who helped organize the festival and was performing at the time of the crowd surge, spoke about the incident in a video posted on Instagram.

“I’m honestly just devastated,” he said. “We’re actually working right now to identify the families so we can help assist them through this tough time.”

Since the event, people have begun sharing their experiences online.

ICU nurse Madeline Eskins wrote in an Instagram post that she “passed out because people were pushing up against me so much that I couldn’t breathe.” Eskins says she was crowd-surfed out and regained consciousness in a chair with a water bottle in her lap. She started helping on-site medics and said she was frustrated at the lack of supplies and medical staff to help people who were “pulseless and blue.”

“The medical staff didn’t have the tools to do their jobs,” she wrote. “And despite the crowd around us trying to get someone to stop the concert, they just kept going.”

It’s unclear what caused the crowd surge. An investigation is ongoing.

This isn’t the first time a crowd surge at a concert has turned deadly. Nine people died at the Roskilde Festival in 2000 when Pearl Jam was playing, and 11 people died in a stampede to see The Who in concert at Cincinnati’s Riverfront Coliseum in 1979.

Verywell asked experts to weigh in on what makes crowd surges so dangerous, and what you can do if you find yourself in an overwhelming crowd.

What Is a Crowd Surge?

A crowd surge is when a large group of people tries to move into a space at once, Steve Allen, lead crowd safety consultant for Crowd Safety, told Verywell. It can include a “crowd collapse,” which is when several people fall down and can’t get back up.

“When it goes wrong is when the crowd collapses and people behind them are going on top of the people in front of them who are already horizontal,” he said.

Allen said that “shock waves” can move through a crowd from excitement and jumping, leading to people falling over.

Every situation is slightly different but, at its core, a crowd surge is a space issue, G. Keith Still, crowd science expert and a professor at the University of Suffolk, told Verywell.

“As crowd density—the number of people in a given area—reaches the point of everyone in close contact, the crowd can begin swaying,” he said. “Any sudden movement in a high-density crowd can result in a surge and progressive crowd collapse.”

Why Crowd Surges Are So Dangerous

Crowd surges increase the pressure in an area, making it hard to breathe, Still said. When people fall on top of each other, they can suffocate from the force, he added.

“Often, people get injured when they either fall or lose consciousness in the midst of the crowd surge,” Mark Conroy, MD, emergency medicine physician at The Ohio State University Wexner Medical Center, told Verywell. “Suffocation has been described in the events in the past as well.”

Another potential issue with crowd surges, Conroy said, is that it can be difficult for people around those who are injured to recognize that there is a problem.

“Getting help to the person can often be delayed,” he said.

How to Stay Safe in a Crowd

It’s important to note that it’s incredibly difficult to protect yourself once a crowd surge has started.

“I’ve seen men that are 300-plus pounds being lifted off the ground in a crowd with their arms in an involuntary movement and they cannot do anything,” Allen said. “What needs to happen is that trained professionals need to be watching and identifying individuals in distress. You need to have competent people doing this.”

Allen said he’s seen mitigation plans for what to do in the event of a crowd surge that involves escalating concerns through many layers of management before a decision is made to stop a show.

“People will be dead in that time,” he said. “It should be a swift, fluid operation to stop the show.”

In general, it is the “job and responsibility of the event organizers to mitigate those risks,” Still said. But he urges people to “be aware of crowd density” in certain situations and “recognize the risks.”

If you’re concerned about the size of a crowd, Allen recommends staying on the edges. “It’s safer on the fringes,” he said.

“If you see pushing and shoving in a crowd, often the best step is moving away,” Conroy said. “This can be difficult given the excitement of the event, but avoidance of the crowd is often best.”

If you find yourself in a dangerous crowd before you can pull away, there are some things to keep in mind, according to Mehdi Moussaïd, a research scientist in Berlin who has extensively researched the movement of crowds.

In an article for The Conversation, he writes that the most important thing you can do is retain your balance and remain upright. If you fall, you’re at a higher risk of injuries. You should also refrain from screaming to preserve the oxygen in your space, as well as try to keep your arms at chest level to protect your rib cage.

Above all, you should try to help others around you. If a crowd of people helps each other in a dangerous situation like this, everyone is better off.

But overall, you shouldn’t have to worry about this at a music venue—it should be up to a venue to protect attendees. “Concerts should be safe,” Allen stressed.