Actor Jeff Conaway, who sci-fi fans know as security chief  Zack Allan on the television series, Babylon 5, and was more widely known for his role as Kenickie in the 1978 musical Grease, and his role as Bobby Wheeler in the late 70’s, early 80’s tv series Taxi, died Friday at the age of 60.

Conaway, who suffered from chronic back problems due to an injury and had repeated back surgeries, had a lengthy battle with substance abuse, which he attributed to his back pain. Conaway was taken to the hospital unconscious on May 11th and placed in a medically induced coma while reportedly being treated for pneumonia and sepsis. On Friday his family removed him from life support.

Conaway is survived by his wife, Kerri Young Conaway; his sisters Carla Shreve and Michele Goffin; and his stepson, Emerson Hall.

Everyone here at SciFi Mafia offer our deepest condolences to Jeff Conaway’s family, friends, fans, and all those who worked with him over the last 40 years.