 Simmons died at his home on Saturday, just one day after turning 76. Tanya J. Powers, Fox News. James Sicking, the Emmy-nominated star of the 1980s police drama Hill Street Blues and of Doogie Howser, M.D., has died. As publicist Cynthia Snyder said in a statement, Sicking died of complications from dementia. I'm Leigh Sillis-Sara. This is Fox News.