Jane Jacobs, who wrote prolifically about the problems and the greatness of cities has died. In The Death and Life of Great American Cities (perhaps the best book ever written about cities), she proposed a vision of urban vitality that incorporated crowding, street life, and diversity, and, in doing so, she changed the way we think about cities. She influenced generations of urban economists, urban sociologists, and urban planners. Proof that ideas, and the creators of ideas, matter.
The New York Times obituary is here.
Slate's obituary is here.