Lois Wille, a Chicago reporter, editorial writer and author who examined, scolded and challenged the city she loved with hard-hitting investigations and won two Pulitzer Prizes, died on Tuesday at her home in downtown Chicago. She was 87.

The cause was complications of a severe stroke, her nephew Eric Kroeber said.

Ms. Wille (pronounced willy) wrote for Chicago’s three biggest daily newspapers over four decades, became a journalistic institution as she exposed scoundrels and prodded the city to do better. She championed its neighborhoods, called for sensible city planning and leaned on the horn to call attention to corruption and graft.

“Power brokers in Chicago admired and appropriately feared Lois,” Ann Marie Lipinski, a former editor of The Chicago Tribune and now curator of the Nieman Foundation for Journalism at Harvard, said in a phone interview. “If she thought you were on the wrong side of history, it could be a withering experience.”

Ms. Wille wrote two books that reflected her deep knowledge of how “the city that works,” as its longtime mayor, Richard J. Daley, called Chicago, really did work. In “Forever Open, Clear, and Free: The Struggle for Chicago’s Lakefront” (1972), she examined the powerful forces that sought to control the valuable stretch of city property along Lake Michigan; and in “At Home in the Loop: How Clout and Community Built Chicago’s Dearborn Park” (1997), she documented the rise of a neighborhood in a blighted city tract in the face of political machinations to thwart it.