Nearly 30 people were suspended upside down in the air for more than 20 minutes after a ride at an Oregon amusement park malfunctioned.

The AtmosFEAR ride at Oaks Amusement Park in Portland stopped working at around 2:55 p.m. Friday, leaving the 28 riders stranded, the park said in a post on X.

Park staff immediately “initiated emergency procedures and called 911,” the park wrote. Emergency responders arrived around 3:20 p.m. and within minutes the ride was lowered and guests were able to safely get off.

Portland Fire & Rescue said all riders were medically evaluated. The park said one person with pre-existing medical conditions was taken to the hospital for further evaluation out of an abundance of caution. The other riders were released at the park by medics.

Daniel Allen and Jordan Harding told NBC affiliate KGW of Portland that they were at the park to celebrate their high school graduation. AtmosFEAR was their first ride of the day.

“I was excited to go on,” Allen told the news station. “When you get stuck up there, I don’t think you’re so excited anymore.”

Harding said when they stayed dangling upside down for more than a few seconds, she knew something was wrong.

“We were just freaking out,” she said. “People were crying. They were just putting into the universe what they wanted to say for their last words.”

Harding said hanging upside down for that long was physically tough.

“My entire waist below was asleep,” she told the station.

Oaks Park describes AtmosFEAR as a “showstopping extreme attraction” and says it is one of its most popular rides. The giant blue and black pendulum is two rides in one, giving guests the option to do the 360-degree swing or the 180-degree swing, according to the park’s website.

It has been in operation since 2021, Oaks Park said in its statement, “and has operated without incident to this point.” Last year, local emergency response teams held an emergency response training at the ride, a standard procedure.

The park said the response plan was carried out effectively during Friday’s incident.

The ride will remain closed until further notice. Oaks Park said it will work with the manufacturer and state inspectors to identify what caused the ride to malfunction.

This article was originally published on NBCNews.com