Backdrop Collapses During John Barrowman's Appearance at Planet Comicon *Updated*

John Barrowman is used to bringing the house down with any appearance he makes at a convention, but I don’t think ever literally. That’s exactly what happened today at Planet Comicon in Kansas City, MO when the backdrop fell behind him. Fortunately the only injury being reported on twitter is a minor one to the sign language interpreter. *Update* The sign language interpreter was not the one injured, despite early…