First off, from the Associated Press:
About 100 people were arrested and at least 44 people were taken to the hospital during a weekend college party in Southern California that devolved into a rock- and bottle-throwing melee, authorities said.
The violence broke out in the densely populated beachside community of Isla Vista around 9:30 p.m. Saturday during the annual spring break party known as Deltopia, the Santa Barbara County Sheriff’s Office said.
Sheriff’s spokeswoman Kelly Hoover said things escalated after a University of California, Santa Barbara police officer was hit in the face with a backpack filled with large bottles of alcohol.
Authorities said some members of the crowd of 15,000 then began throwing rocks, bricks and bottles at officers, lighting fires and damaging law enforcement vehicles.
Just look at these photos and videos.