Typically during Halloween Horror Nights, the following attractions are open:
Back to the Future
Men in Black (beware of VERY long lines on this one)
Jaws (with added Scaractors in boat house)
Twister
T23D
Kong is closed since the street level of the attraction is used as a haunted maze
None of the daytime shows operate since their theatres are used for HHN shows (i.e. Bill & Ted take over Wild West)
Earthquake (ride only) was operating last year as a sort of preshow to one of the mazes in it's queue.
Occassionally, on peak nights ET is added.