The Sky Cabin became stuck with 21 people, including seven children, onboard, according to the Orange County Fire Authority. Knott's Berry Farm stated the ride stopped at about 2 p.m.
Knott's Berry Farm said it made several attempts to lower the attraction before eventually calling fire officials. Fire crews said they were called to the scene just before 5 p.m.
Firefighters attempted to reach the stranded passengers by ladder, but the ladder was too short to reach the cabin.
OCFD said it attempted to use a gravitational system to slowly lower the ride, but that proved unsuccessful.
Fire crews opted to use a rope and harness system to lower each passenger one-by-one.
"We have firefighters in the cab with the occupants. No one is in any medical distress. So we're going to affix a harness onto each one of them and one at a time we're going to lower them down to the ground," Orange County Fire Authority Capt. Larry Kurtz said.
The revolving observation deck stopped moving with one man's three daughters onboard. Eddie Kim said the ride just stopped midway, and once one of his daughter's was rescued, he waved at her as she came down.
His daughter high-fived her rescued as she came down. Kim said he wasn't worried about the situation.
"This is America. We (are one of the safest) countries in the world," he said.
"It sounds scary, but these guys, they train for this all the time," Kurtz said. "We have very, very strong ropes that have 9,000 pounds of breaking strength on them."
A company that provided a cherry picker in another attempt to reach the stranded riders said based on their measurements, the ride was stuck 148 feet in the air, as opposed to previous reports that it was between 120 - 130 feet high.
As rescue efforts began, the fire authority was asked by Knott's Berry Farm's public relations team to stop giving information to the public.
All 20 passengers and one ride operator were brought to the ground safely shortly before 10 p.m., according to Knott's Berry Farm representatives.
In a statement, theme park officials said rides are always checked.
"Each of Knott's rides is inspected, check-listed and properly maintained daily. Sky Cabin will remain closed until the park's investigation into the cause of the incident is completed," it said.
The ride remained stopped at the halfway point.