An Austrian security guard stands in front of the entrance of Mauer hospital where the family of Josef Fritzl is receiving psychological treatment near Amstetten, eastern Austria May 2, 2008. Josef Fritzl, a 73-year-old electrical engineer, who imprisoned his daughter for 24 years and fathered seven children with her had threatened to kill his victims by pumping gas into the cellar where he was holding them, police said on Thursday. REUTERS/Leonhard Foeger (AUSTRIA) | Foto: Reuters