BBC, Elisabeth Sladen passed away yesterday morning after a long bout with cancer. She was 63. As an actress, her most well known role was when she played Sarah Jane Smith in the British television program Doctor Who back in the seventies. She also also starred in two different Doctor Who spin-offs, K-9 and Company and The Sarah Jane Adventures. Out of all the actors and actresses who appeared on Doctor Who playing one of the Doctor's companions, she was probably the most well liked. Whenever I would see her in an interview she always came across as being very professional. She also seemed to really care about people. She will be greatly missed.
EDIT: Tom Baker has a really nice tribute to Elisabeth here.