The Phoenix Wheel will be taken apart and reinspected when it returns from Port Townsend.
A malfunction apparently caused the cart they were riding in to flip, causing them to fall 15 to 18 feet onto the ride's metal platform.
Janke-Call said they were stuck in the air on top of the Ferris wheel for about 30 minutes after the incident.
An injured 59-year-old woman had to be airlifted to a hospital. The older woman suffered the most serious injuries. She was transported to the hospital at around 7 p.m. Thursday in critical condition.
People fell from a height of nine meters.
Just a few weeks before the Rose Festival brings City Fair to the Portland waterfront, a Ferris wheel accident in Washington is raising questions about ride regulations and safety.More news: Sheffield Wednesday and Huddersfield Town clash for place at Wembley
"This is about as bad as it gets in the amusement ride business".
The Washington Department of Labor and Industries says while all rides are inspected, that's not a guarantee against accidents.
The operators did not appear to notice immediately.
Brandi Hamon and Debbie LaFollette, the vice president and president, respectively, of the Rhododendron Festival, said in a joint statement, "First and foremost the Rhododendron Festival would like to ask for everyone to please pray for all the victims in today's carnival accident". This was a tragic event and our thoughts and prayers are with all involved.
The festival said authorities and the company that owns the carnival equipment are investigating. Thank you to all the volunteers and employees that stepped up out of the crowd to make sure the victims were attended to and the incident was controlled.