Six Flags Discovery Kingdom (AP Photo)

VALLEJO, Calif. (AP) — A spokeswoman for a Northern California amusement park says a dozen people were stuck on a roller coaster for almost two hours after it stalled 150 feet in the air.

Six Flags Discovery Kingdom spokeswoman Nancy Chan tells the Vallejo Times-Herald that the Superman Ultimate Flight roller coaster stopped at about 2:30 p.m. Sunday at the top of the ride, just before a twist.

Vallejo firefighters arrived at about 3 p.m. after receiving a rescue request. But a park mechanic eventually restarted the ride, which then went backward and lowered the riders safely to the ground.

Fire Battalion Chief Ray Jackson says none of the stranded riders were injured.

The new ride opened June 30 at the Vallejo theme park and can travel at up to 62 mph. It holds two cars with six riders each.