Actress Elisabeth Sladen was best known in her role as Sarah Jane, the fourth (and tenth) Doctor's courageous, plucky journalist companion on Doctor Who.
The BBC is reporting that she has passed away--of cancer. I didn't encounter Sladen/Sarah Jane until her appearance in the new Doctor Who series, but said introduction provided an entry point into older Who episodes.
Thanks, Ms. Sladen, for creating a memorable, admirable character.