Dan McGrath was chosen to write the episode , while Jim Reardon directed . The episode was originally produced as the season finale of the fifth season , but was held over and aired as the premiere of the sixth . This was because , along with " Lisa 's Rival " , the episode was in production at the time of the 1994 Northridge earthquake . The earthquake damaged much of the Film Roman building in which '' The Simpsons '' writing and animation staff worked , forcing them to move out for three months and continue production in a temporary building . The only staff members that came in expecting to work were future show runners Bill Oakley and Josh Weinstein . As a result , the staff was given a month more than they would usually have had to work on the episode , which Reardon described as " greatly benefiting " it . Having been a director on the series for five years before this episode , he believed that this " was closer to what he was trying to achieve as a director than he had done before " . He credited this to the extra time , and used it to insert little details , such as having Bart get stuck on the fabric of the chair he was in , and wearing his underwear instead of a swimsuit
1994 Northridge earthquake
1994 Northridge earthquake
Bart of Darkness