State Department of Occupational Safety and Health inspectors responded within about two hours of Friday's crash, then returned at 8 a.m. Saturday for about seven hours. Investigators are trying to figure out why one ride car smashed into another car as 48 passengers were concluding the ride.
Len Welsh, the department's acting chief, said a "coordination" problem occurred with the arrival times of the two coaster cars. The operator or computer is likely to blame for the crash, Welsh said.
Other ride experts agreed.
In six or so similar cases, an operator was responsible for coaster collisions, said Ed Pribonic, a private ride consultant based in Seal Beach. Unless the ride's computer program was recently changed or a sensor broke down, he said, human error is probably to blame.
"It's highly unlikely that any error would spontaneously occur. That's almost an impossibility," Pribonic said.