Dozens of people were arrested and at least 44 people were taken to hospitals for treatment after the spring break brawl in Isla Vista Saturday night.
Sheriff's officials say a major disturbance broke out around 9:30 p.m. in the 6700 block of Del Playa Drive.
A UC Santa Barbara police officer needed more than 20 stitches after being hit in the head with a backpack full of alcohol. Investigators say another officer was smacked in the face with a brick and needed multiple stitches.
Half a dozen officers were hurt when revelers through bricks, bottles and rocks at them as they moved in to squash a riot that broke out.
Some people ripped up stop signs, lit several small fires and damaged property, including several law enforcement vehicles.
Police lobbed tear gas, pepper spray and foam projectiles to disperse the out-of-control crowd. It took several hours for law enforcement officials to restore order. Witnesses say it was scary.
"I don't want to see this event happen again. It's scary even if you just hear rubber bullets. It's scary hearing people and seeing people get shot," said student Briana Drago.
Sheriff's officials say the whole melee was sparked when police tried to break up a fight between partygoers.
"It just kind of spawned this mob mentality 'us versus them,'" said sheriff's spokesperson Kelly Hoover. "Preliminary indications are that about 80 percent of those who were arrested or cited are from out of the area."
Officials briefly detained about 100 people. They say the suspect who seriously injured a UC Santa Barbara police officer is a juvenile. They are on the hunt for other suspects. They say this traditional party, which draws around 15,000 people, needs to end.
"This is an unsanctioned event. It's dangerous. Last year, we had a woman fall off the cliffs and die. We had a balcony collapse and several people were seriously injured," said Hoover.
UC Santa Barbara released a statement, calling the partygoers' behavior "outrageous and extremely dangerous."
"Any of our students found to have violated the law or University policies are subject to University sanctions," the statement said.