In a departure from past accident investigations, the state also ordered Disney to inspect similar brake parts at all its other parks including those outside California and implement the same corrective action. Disney officials took it a step further by issuing a bulletin about the valve failure to the entire theme park industry.

According to the report, the accident occurred shortly after Disney maintenance workers replaced several brake parts on the ride because of "an ongoing problem with the air line leaking due to the age of the parts and deterioration."

The original valves had been manufactured by a company called Intamin, the report said, but Disney used a different brand because Intamin parts were unavailable. The second brand, Legris, was "more prone to malfunction," state investigators said. In addition, it was made of a different material and was a different diameter.

Shortly after the parts were installed, Disney maintenance workers reported a leak in the new brake valves, the report said, but later inspections yielded no signs of a problem.

"We thought the problem had fixed itself," Doughty said, adding that the brakes were tested several times before the accident.

In its report, the state ordered eight corrective actions, including redesign of the brakes, retraining the maintenance crew to fully document their work and the reviewing of procedures for testing mechanical systems after major maintenance.

Disney has met all of the state's requirements, Doughty said, except the review of testing procedures, which is due by Nov. 18.