Tragic news about Brian Doherty. Though I didn't know him well personally, I long admired his writing, especially Radicals for Capitalism, his definitive history of the modern libertarian movement up to the early 2000s.

Brian Doherty, historian of the libertarian movement, dead at 57
The longtime Reason senior editor accidentally fell to his death from a park along the San Francisco Bay. He was 57.
reason.com