Cal Poly Festival Revelers Rampage in San Luis Obispo : Riot: Cars, homes and businesses are vandalized by mobs. Tear gas and high-pressure water hoses are used by police.

An annual spring festival at Cal Poly spawned a violent melee in the city streets Friday night and early Saturday as more than 1,000 revelers vandalized cars, homes and businesses before police used tear gas and high-pressure water hoses to disperse the mobs.

The crowd hurled bricks, rocks and beer bottles at police, who called in reinforcements dressed in full riot gear from throughout San Luis Obispo and Santa Barbara counties. A dozen police officers were injured--including one who suffered a broken arm and another who lost a tooth when he was hit in the face with a bottle.

Thirty people, about half of them Cal Poly students, were booked at San Luis Obispo County Jail on suspicion of disturbing the peace, assaulting a police officer and other offenses.

The festival continued as planned Saturday night--including a rodeo competition and a concert by the rock band Santana. Police, who had geared up for the possibility of another night of violence, said late Saturday that there were no major problems.

Authorities said the violence that began Friday night included at least three outbursts and did not end until about 2 a.m. Saturday. Witnesses said roaming vandals caused widespread damage in a residential area on the north side of the city, with young people smashing car windows, tearing down street signs, climbing on roofs and urinating in public.

In one case, a crowd chanting “Free beer! Free beer!” smashed the windows of a liquor store and began tossing beer bottles into the store, while frightened employees pitched full champagne bottles back out the broken windows to keep the unruly crowd at bay. The shop owner said the police took 30 minutes to respond. Police acknowledged that they were busy trying to quell another rampage a few blocks away.

“It was incredibly chaotic,” said senior Heather Wicka, who witnessed the scene from her front porch. “There were masses of people lined up. They were standing on cars, they were standing in the street. They were climbing telephone poles, street signs until they knocked all the street signs down. It was like a shark-feeding frenzy, just animal aggression.”

Said Michael Bronkey, a local radio disc jockey who happened upon the scene: “It was the most incredible thing I’ve ever seen. The police were chasing people, beating on people and everyone was screaming. I was just standing there in awe. It was a strange event, a strange night.”

The fracas has cast doubt upon the future of the Poly Royal Festival, a 58-year-old campus tradition that draws upwards of 100,000 people to this central coast city of 41,000.

University President Warren Baker said that he intends to bring administrators, faculty and students together to “look at the situation, evaluate what happened, why it happened, and the consequences for the future.”

In its early days, Poly Royal was billed as “a country fair on a college campus,” according to one professor. On campus, it is sort of a gigantic show-and-tell in which students display their architectural, agricultural and engineering projects--from homemade jams and cheeses to models of cities.

But off campus in recent years, the festival has grown into a rowdy weekend of partying that has annoyed local citizens. “People are sick of it,” said Ray Tippo, who teaches journalism at the school.

During last year’s Poly Royal, what police described as a “mini-riot” erupted in an off-campus student apartment complex. Police Lt. Ron Orback said that while that disturbance was not as severe as this weekend’s, it was “a real mess,” with hundreds of people hurling bottles off rooftops and “just raising heck.”

“It’s been gradually getting worse over the last few years,” said Sgt. Leon Cole of the San Luis Obispo County Sheriff’s Department. “I’ve had officers tell me that (Friday) night was about 10 times worse than last year.”

In the wake of last year’s trouble, the university placed a heightened emphasis on the academic side of Poly Royal. In a statement released Saturday, student body President Ricardo Echeverria said: “The students of Cal Poly are very aware of the real intent of Poly Royal--that of displaying the academic aspects of our campus. We, as students, have worked diligently for the past year to preserve and promote this theme.”

The statement, released jointly by the university administrators, the student government and Mayor Ron Dunin, praised the police response as “appropriate and measured.” City officials blamed much of the problem on out-of-town visitors.

No one seems to know what sparked the disturbances Friday night, although Orback said, “the main problem is alcohol.” In all, more than 80 law enforcement officers were called in to restore order.

Authorities said the melee began at 10:30 p.m., when police and paramedics were rushing to get to a traffic accident just south of the campus. As paramedics tried to assist the victim, revelers began throwing things at them.

About 30 officers tried to clear the scene. But before they could finish, they were called off to another disturbance several blocks away. “They were met with a barrage of bricks, rocks, pieces of tile, street signs and other items,” according to a police statement.

Using loudspeakers, the officers tried to persuade the crowd to disperse. Then, according to freshman Heath Patton, they got creative: “The cops started blaring on the p.a. system, ‘Assault on police officers will not look good on your resume!’ ”

The riot did not break up until the police resorted to spraying the crowd with water and tear gas. Meanwhile, at yet a third site, John Martin, owner of the Campus Bottle liquor store, had already shut down his business--four hours earlier than usual.

“The crowd was too big outside and it was getting to where I couldn’t control the number of people coming in,” he said. “So we closed up, hoping they would have all gone away and cleared out.”

But the revelers demanded more beer. They smashed his windows with a stop sign. Soon, the “bottle war,” as one spectator called it, was under way. “We were exchanging projectiles,” said Martin, adding that he and his employees were afraid to leave the store. “We didn’t have any place to go. The building was surrounded.”

Eventually, the police came. When it was over, a truck drove by, its large headlights illuminating the street.

“What you could see was the glittering of glass,” said Wicka, the student who had watched from her porch. “The street was actually wet from alcohol, from beer. And the gutters, all of them were filled up to curb level on both sides with glass and cans.”