Video obtained by Eyewitness News shows first responders arriving at Bishop Conaty - Our Lady of Loretto High School in the Pico-Union area around 9 p.m.
The ride, commonly known as The Zipper, appeared to have stopped mid-ride with people inside. A witness can be heard saying that some of the riders were trapped for up to an hour.
No injuries were reported.
The school was hosting a "Family Fun Day" event with carnival rides, food, live music, and a petting zoo.
The Archdiocese of Los Angeles sent Eyewitness News the following statement:
"We are grateful that no one was injured over the weekend when a carnival ride, operated by a third party, experienced a malfunction at a Bishop Conaty High School event. We are very thankful to the first responders who arrived to help. The event was able to proceed as scheduled. The safety and well-being of all in our parishes, schools and ministries remain our top priority."