Kitty Carlisle Hart, whose long career spanned Broadway, opera, television and film, including the classic Marx Brothers movie "A Night at the Opera," has died at age 96, her son said Wednesday.

Christopher Hart said his mother had been in and out of the hospital since contracting pneumonia over the Christmas holidays.

"She passed away peacefully" Tuesday night at her Manhattan apartment, said Hart, who was at her side when she died. "She had such a wonderful life, and a great long run, it was a blessing."