Peter Kaplan, the former editor-in-chief of The New York Observer, passed away at 59 after a battle with cancer. From 1994 to 2009, he turned a small-circulation paper into one of the most influential voices in media, mentoring a who’s who of modern journalism. Kaplan’s Observer was a mix of wit, erudition, and insider savvy, leaving an indelible mark on New York’s media landscape.