When I'm reloading my saves ,Hassan is disappear and apparently cannot die. Clicking him reveal that he's using a pole. Try to reload save earlier days but more dupes find their way to disappear. I find that especially when using fire pole cause dupes animation to freeze for a while and return to normal when climbing or doing something again and sometime dupes jump in random tiles when using fire pole and sometimes when I don't look at them when using the pole, they seems to be stuck up there. (One dupes have died and others made a big mess.) Just trying out a new fire pole this patch. I'm happy with it but still many bugs.