Morningwood Penitentary was a once-abandoned prison in Springfield. It was re-opened by Mayor Quimby who wanted to use the prison's electric chair "to send a message to the criminals of Springfield". Before its reopening, Morningwood was patrolled by a single elderly guard who kept away trespassers.
It was originally abandoned, however, Mayor Joe Quimby decided to reactivate the Springfield Penitentiary. However, neither the Police Force nor the Mayor realized the day of its reopening that Bart Simpson and Ralph Wiggum trespassed into the abandoned building the night before with Wiggum's master key and played with the Electric Chair. Lisa, Bart, and Ralph attempted to warn them by firing a rocket containing a note saying "The Electric Chair is on" to the Penitentiary. However, while it didn't make it to the penitentiary, it did make it to the next best location: Mr. Burns's office at the Springfield Nuclear Power Plant, which caused him to turn off the electricity.