PITTSBURGH (AP) — The Mike Tomlin era in Pittsburgh is over. The longest-tenured head coach in major American professional sports stepped down from his job leading the Steelers on Tuesday after yet another quick playoff exit. The announcement came a day after the end of his 19th season in Pittsburgh, where he was a relative unknown when he was hired to replace Bill Cowher in early 2007. “Obviously, I am extremely grateful to Mike for all the hard work, dedication and success we have shared over the last 19 years. It is hard for me to put into words the level of respect and ...