Tony Horwitz, the Pulitzer Prize-winning journalist, historian and author whose books have graced best-seller lists and college syllabuses, has died at the age of 60. His publisher confirmed to NPR that he died Monday without warning, while in Washington, D.C., on tour for his most recent book, Spying on the South: An Odyssey Across the American Divide

He collapsed and died while walking near his brother’s home in the District, said his wife, Geraldine Brooks, the Pulitzer-winning novelist. An autopsy has not been completed, but his wife said an attending physician at a hospital cited cardiac arrest.