05/08/2010 05:12 am ET | Updated May 25, 2011

March 4: Students, Professor Hurt (WATCH)

**UPDATED: An earlier version of this story reported that Karren Baird Olson was injured during a protest at California State University in Fullerton. The protest occurred at CSU's Northridge campus.

Videos emerging from March 4's Student Day of Action in California show tension and violence between students and police.

At the Northridge campus of California State University, Karren Baird-Olson, a 74-year-old professor of Sociology, American Indian Studies and Criminology was trampled when members of the Los Angeles Police Department clashed with protesters, who had been chanting "peaceful protest." Baird-Olson suffered a broken arm and other injuries.

WATCH: The CSU skirmish

A pack of marching students at the University of California-Davis was repeatedly shot at by police with pellet guns. When one protester strayed from the group, she was beaten by police, which can be seen in this video, produced by the UC Davis student television channel: