On Hill Street blues, S3, E8, Dominique Dunne made her final appearance before she was killed.
Apparently, they didn't need to do much makeup on her as she was beaten the night before filming by the abusive boyfriend that ended up murdering her.
[ You are not allowed to view attachments ]
The Poltergeist curse also got to the director of this particular episode who died of cancer 2 weeks after it aired.