There has been no explanation as to why Bergman committed suicide, and attorney Robert Harrison says that she had shown no signs of depression. Ironically, her career was at a peak at the time of her death because of her roles in ''The Family Guy,'' ''The Iron Giant,'' and ''The Phantom Menace'' as well as ''Park.'' In an interview with EW Online several months before her death, the 38-year-old performer credited ''South Park'' for pulling her out of a typecasting rut. ''I'm known for these sweet, cute little characters,'' she said, noting her roles in ''The Lion King'' and ''Beauty and the Beast.'' ''So I've been doing them forever. My agents were trying to submit me on shows that are edgy, and they're laughing, 'Mary Kay, are you kidding? No way!'''
Initially Bergman used the alias Shannen Cassidy (taken from stars Shannen Doherty and David Cassidy) on ''South Park'' as a way to distance herself from her cute reputation, but she later abandoned the moniker. ''It was a conscious decision to be anonymous at first, because none of us knew the show would be a hit, and if anyone tells you they did, they're lying,'' she said. ''Then it did hit, and Shannen Cassidy was getting mail like Santa Claus, so we transitioned out of it.''
Not only had Bergman's career blossomed of late, but so had her voice-over skills. ''I have more of a range as I've gotten older, not less,'' she said. ''I also think it has to do with my lack of timidity now. I did the voice of a 13-year-old adolescent yesterday, and I don't think I would have found the guts to do it years ago.''
Still, she said that one role was never easy to play. ''A lot of times I do commercials where they say, just be you, just be yourself. It's very hard. Very hard.''