in 1697, Bart Simpson escaped Snowpaw Correctional. He tunneled out through the wall under that poster of his. I remember laughing when I read about the Simpson wedding in 1698, how the Cops where hauled out by Steven and Elsa by their shirts. Back on topic, Bart probably meant to carve his name in the wall, or Bart loves Anna, but it crumbled and created a tiny hole... one Bart worked on.