Lawmakers on Capitol Hill are pushing to regulate trampoline parks amid mounting concern over their risks. A California police officer filed a lawsuit last week after he was temporarily paralyzed at a trampoline park outside San Francisco in 2013.
Arevealed six deaths since 2012 and a number of severe injuries at the popular parks. Two weeks ago, CBS News' Meg Oliver went to a Chicago-area trampoline park to assess the potential dangers. Less than an hour before her arrival, Jason Freewalt, a healthy young dad and former college football player, suffered serious injuries to his legs.
The 42-year-old could hardly find the words to explain the pain of jumping into a foam pit at Get Air trampoline park near Chicago. His 11-year-old daughter saw it happen.
"I can't describe it. It was one of the most painful things I've ever had," Freewalt said. "I said please run, call 911. I can't move, I blew my knees out."
Freewalt ruptured both of the patellar tendons in his knees, requiring emergency surgery. Oliver arrived at the park with trampoline expert Don McPherson less than an hour after Freewalt was taken to the hospital.
McPherson has coached elite gymnasts for more than 40 years and testified in hundreds of plaintiff cases against trampoline parks.
Since our first report on trampoline park dangers aired last month, McPherson tells us 11 attorneys have asked him to be an expert witness in their cases.
"I got slammed by attorneys all over the country," McPherson said.
The injuries involved in those cases, according to McPherson, include two broken necks, broken ankles, open fractured elbows and "half a dozen open tib fib fractures."
Sen. Richard Blumenthal is sponsoring legislation that would hold businesses accountable for the injuries occurring inside trampoline parks. In many cases, visitors sign waivers with forced arbitration clauses, meaning they give up the right to take their cases to court. Sen. Blumenthal is sponsoring the Fair Act which would eliminate forced arbitration clauses in consumer cases, among others.
"I was horrified as a parent, not to mention a public official," Blumenthal said. "Trampoline parks want to avoid justice. They want to rig the system against anyone who is injured who may assert claims against them."
Blumenthal said the parks are "trying to hide individual deaths, the total number. Everything about these injuries that may cast them in a bad light."
In 2011, there were an estimated 40 trampoline parks nationwide. Now, that number has jumped to more than 800 and there is no federal oversight, only voluntary safety standards.
In a recent statement, the Consumer Product Safety Commission told CBS News it is "doing investigations to determine whether we can take action to protect consumers."
"Congress should have a role here ... but the biggest deterrent to death and injury at these parks will be the park owners being hauled into court, held responsible, deemed culpable, having to pay," Blumenthal said.
Freewalt, who did sign a waiver to enter the Get Air trampoline park, now faces months of rehabilitation. He wants other families to know about the potential dangers.
"When you go to places like this, you sort of trust in the fact that things are safe," Freewalt said. "I would tell any family out there, do not go to these trampoline parks."
CBS News reached out to the park where Freewalt says he was hurt but they didn't return our calls.
The world's largest trampoline park company, Circus Trix, told us in a statement that, as with any sport, there are inherent risks, but they are committed to ongoing safety evaluations and take numerous measures to reduce risk at their parks.