WASHINGTON — Concepcion Picciotto, the protester who maintained a three-decade peace vigil outside the White House that was widely considered to be the longest-running act of political protest in U.S. history, has died.

The Washington Post reports (http://wapo.st/23qW3F7) Picciotto died Monday at a housing facility for homeless women. Schroeder Stribling, executive director of N Street Village, says Picciotto had recently suffered a fall, but the cause of death was not yet known.

Picciotto, a Spanish immigrant, was the primary guardian of the anti-nuclear-proliferation vigil stationed along Pennsylvania Avenue. She was quoted in 2013 as saying she protested to "stop the world from being destroyed."

Fellow protester Ellen Thomas says she, husband William Thomas and Picciotto formed a group whose nuclear disarmament campaign was known as Proposition One.