It’s been a terrible and tragic week for journalism. NBC suspended anchor Brian Williams over exaggerations about his reporting in Iraq; Jon Stewart announced he’s leaving The Daily Show. Then, Wednesday night, 60 Minutes correspondent Bob Simon was killed in a car crash. And yesterday, New York Times media columnist David Carr collapsed in the newsroom and died. He was 58. Carr’s obituary was front and center on the Times’ website this morning. He covered the media, but his writing transcended his beat. And in recent years, he’d become an unlikely public face for the New York Times.