For those who remember it, the chaos and disruption plaguing the campus of Columbia University are drawing parallels to a similar demonstration that occurred in April 1968.

Fifty-six years ago, a group of students occupied areas and buildings on campus, including the academic building Hamilton Hall, as an act of protest against the Vietnam War and Columbia’s plans for a gymnasium. The illegal demonstration culminated in police action that took place in the wee hours of the morning of April 30, 1968. The New York City Police Department used tear gas to clear the occupants, and more than 100 students were injured along with 12 police officers. Over 700 people were arrested.