"Excessive corrosion" caused the Fire Ball ride collapse which killed one person with seven injured in US state OH last month, the manufacturer said Sunday.
Relatives of 18-year-old Jennifer Lambert say she's opened her eyes briefly but hasn't woken up.
Four of the injured remained hospitalized last week, including an 18-year-old woman in a coma, and Jarrell's 18-year-old girlfriend.
The company said it conducted an investigation into the incident, which included a visit to the scene and a review of video footage of the incident.More news: Israel attempts to shut down Al Jazeera's office and ban journalists
The ride at the OH fair was 18 years old, the company said.
The teen had just enlisted in the Marine Corps and was about to head to basic training next year. Jarrell's family has hired an attorney to possibly pursue a wrongful death lawsuit.
Despite the manufacturer's claims, previous reports from the Cleveland.com note that the ride had been inspected at least three times both by state officials and a third party, and was cleared for operation when the fair was set up prior to opening.More news: Toyota's big future bets include robots, M&A and self-driving cars
Albert Kroon, the product manager for KMG, which makes the ride, said KMG is collaborating with other safety experts in the industry to create a better safety and inspection protocol that will keep other accidents like this from occurring, CNN reported.
The ride's manufacturer, KMG, announced investigation results Sunday, almost two weeks after the accident.
Amusements of America, the company that provides rides to the state fair, said its staff also had inspected the ride.More news: Gopalkrishna Gandhi got more votes than Meira Kumar, says opposition