King had come to Memphis to support striking sanitation workers whose signs read 'I AM A MAN' -- a simple declaration of human dignity. The march deteriorated when some participants broke windows and looted stores. Police responded with tear gas, clubs, and gunfire, killing a 16-year-old. King was devastated: the violence undermined his philosophy of nonviolent resistance. He insisted on returning to Memphis to lead a peaceful march, determined to prove that nonviolence could still work. One week later, on April 4, he was assassinated on his motel balcony. His last campaign was about the most basic civil right: the right to be treated as a human being.