Fifty years ago, a student sit-in at UW-Madison turned violent and became a seminal event in local and national history related to the Vietnam War. Called the "Dow riot" -- after the makers of napalm, a brutal chemical weapon used in the war -- it started because students were protesting Dow Chemical's presence as a recruiter on campus. The university ordered the students to disperse, and they didn't, then called in Madison police. Police beat students, and the confrontation escalated. By the end of the day, the city would never be the same.