Six Flags New England is canceling plans to build the Dark Knight roller coaster. The project was delayed several times as the city of Agawam issued stop-work orders citing changes to the approved plans that were originally submitted. There were other issues with the State of Massachusetts Department of Public Safety concerning a fire suppression sprinkler system and emergency exits from the roller coaster building. According to park spokeswoman Melissa Pinkerton, work that has already been done will be dismantled. The coaster, a Mack wild mouse, has most likely already been constructed, and Six Flags, Inc. may have difficulty canceling the order. It is possible the coaster could be constructed at another Six Flags park, but probably not this year. In the meantime similar Dark Knight coaster projects are progressing without problems at Six Flags Great America in Illinois, and Six Flags Great Adventure in New Jersey. Both are expected to open next month.