BOWIE, Maryland (KABC) -- Riders had to be rescued when a roller coaster got stuck at the top of its peak at a Six Flags amusement park in Maryland.A car on the Superman: Ride of Steel coaster at Six Flags America locked up near the top of the 205-foot high ride Monday.Park workers were able to evacuate and rescue several riders who were on board the coaster prior to the arrival of rescue crews.The coaster car itself remained stuck on the track for some time after the riders were rescued.The Superman: Ride of Steel roller coaster reaches speeds up to 73 mph as it races, drops and twists along more than a mile of track. It opened in 2000.