Her co-star, Noel Clark, who played Mickey Smith in the 2005 reboot of the cult program, tweeted: "Sarah Jane Smith lives because Elisabeth Sladen made her Great. -Liz, you were awesome and will be missed. (no more to be said tonight)."
Born Feb. 1, 1948 in Liverpool, England, Sladen began dancing at an early age before turning to acting in the 1960s. After a series of plays and television appearances, including a six-episode stint on the popular British soap opera Coronation Street, in 1973 the thesp landed the role that came to define her: that of Dr. Who's favorite companion (and ardent feminist) Sarah Jane Smith, who investigated all kinds of sci-fi doings and faced off against various adversaries such as the alien Dalek and the Cybermen.
After exiting the series following her third season in 1976, she returned periodically over the next several decades until she ended up being offered to reprise her alter-ego in the spinoff series, The Sarah Jane Adventures, which debuted in Feb. 2007 and ran for four series.
"We had a glorious time," Russell T Davies, who masterminded the Dr. Who reboot as well as the Adventures series, told the BBC. "It's just so sad. It was a joy to know the woman and an honor to have worked with her. Seriously, I loved her."
No word on the status of a fifth series which was supposedly in the works until news of Sladen's death.