On most weekends, trampoline parks are at capacity with hundreds of kids bouncing, jumping into pits, and playing tag. The popular theme parks have exploded into a billion-dollar industry. But in the last seven years, CBS News has confirmed at least six people have died from injuries at trampoline parks. That number could be even higher because many of those injured are often forced into arbitration and sign confidentiality agreements that stop them from speaking out, reports CBS News' Meg Oliver.

The parks' popularity is leading to new cases for attorneys like David Chazen, who represents more than a dozen people injured at trampoline parks in New Jersey. In one video of a trampoline park that he showed us, you could see a father unknowingly causes what's known as a "double bounce." His 4-year-old son falls to the mat. "The force of the trampoline coming back up after the father's hop across broke the 4-year-old's femur," Chazen said.

It took almost a full minute before anyone, including the guard on duty, realized the child was squirming in pain.

State lawmakers in Utah recently passed a new law to try to make trampoline parks safer. Utah joins at least seven other states requiring more oversight from insurance companies and annual inspections. In the U.S., all of them operate without any federal oversight.

Don McPherson has coached gymnastics for more than 40 years. Since 2011 he's been an expert witness in more than 200 plaintiff cases against trampoline parks. He said the injuries they can cause are life-altering.

"Broken necks, broken backs, dislocated and open-fractured elbows, shoulders," McPherson said. "They're all catastrophic injuries."

McPherson said the danger lies in the design. Several trampolines are connected with steel cables or chain links under thin padding. As people jump, waves of energy are generated in all directions, which can cause those "double bounces" that can end in high-impact collisions.

"They're moving at speeds and with energy that when they hit or get hit by somebody else that's twice their weight, they end up with crush injuries," McPherson said.



The injuries are so severe they can lead to death.

At his peak, Ric Swezey was a world-class gymnast.



"Other than his children and me that mattered most to his life was his gymnastics," husband Nick Scandalios said.

That all changed in 2017 when Swezey visited a trampoline park in Virginia with Scandalios and their twins. Scandalios said Swezey was jumping on the trampoline when he came down wrong on his foot, stumbled, and hit his head against a thinly padded wall.

"The C2 vertebra cracked, constricted his airway and his blood flow, paralyzed him. He was over 90 percent brain dead," Scandalios said.

"Within three minutes you lost the love of your life," Oliver said.



"Yup," Scandalios said, choking up with emotion. "I watched the lights go out in his eyes."

In the last few years, emergency room visits caused by trampoline park injuries has skyrocketed. According to the Consumer Product Safety Commission, the numbers have shot up from 2,500 in 2013 to almost 18,000 in 2017.

"Everyone in the gymnastic community calls them death parks," McPherson said. He took us to a trampoline park outside Chicago. "This whole set-up is wrong," he said, pointing out several red flags – from lack of supervision to trampolines flush against thinly padded walls.

"How dangerous is that?" Oliver asked.

"Dangerous," McPherson said. "This can cause a brain bleed."

He also said the foam pits adjacent to trampolines were too shallow. People are "unknowingly" risking their lives at these trampoline parks, he said.

For families like Scandalios', the message is simple: "Never. Birthday parties, no. Never. Never. Never. Never."

In response to the deaths and injuries, the International Association of Trampoline Parks told CBS News: "There are parks that do not adhere to industry technical standards, and do not operate with safety at the forefront of their agendas." The group has launched an initiative to require third-party inspections to ensure the safest experience possible.