Doobie Brothers drummer Keith Knudsen, who found country success in the '80s with Southern Pacific, died of pneumonia Tuesday (Feb. 8) in San Francisco. Knudsen, 56, joined the Doobie Brothers in 1974 and remained in the band until a farewell tour in 1982. Knudsen and Doobie Brothers guitarist John McFee later teamed with singer Tim Goodman to form Southern Pacific, adding keyboardist Kurt Howell and former Creedence Clearwater Revival bassist Stu Cook before the release of the band's self-titled debut album in 1985. Southern Pacific released four albums and four Top 10 singles -- "Reno Bound," "New Shade of Blue, "Honey I Dare You" and "Any Way the Wind Blows" -- before breaking up in 1991. Knudsen returned to the reunited Doobie Brothers in 1993.