Youths Rampage at Theme Park and Nearby Businesses : Crime: People turned away from overcrowded Magic Mountain are blamed for robbing, vandalizing in vicinity. Later, looting and vandalism break out in park and 20 are injured.

Hundreds of youths rampaged Saturday through Magic Mountain and the area surrounding the amusement park near Santa Clarita, firing shots, stoning deputies, breaking windows, looting and robbing stores and restaurants, and vandalizing cars.

About 650 Los Angeles County Sheriff’s Department and California Highway Patrol officers were dispatched to the park to try to control the situation.

The Sheriff’s Department said gunfire was heard in the park’s employee parking lot. The county Fire Department sent three ambulances to the park and said 20 people were being treated for minor injuries related to panic.

Sheriff Sherman Block said the violence was “totally unrelated to the verdicts” in the Rodney G. King civil rights trial, though a park spokeswoman had noted earlier that many of those who jammed the park Saturday were celebrating the two guilty verdicts.

The disturbance began as a protest against the overcrowded park’s closing of its gates to more admissions in the afternoon while thousands of patrons were still outside, many of them holding tickets to an evening concert by the hip-hop groups TLC and Paperboy. The closure created a massive traffic jam, which at one point extended eight miles south along the Golden State Freeway.

The park was closed because it had reached its capacity, said Eileen Harrell, a park spokeswoman. She said the park can hold more than 20,000 people, but Block put its capacity at 35,000.

Harrell said the order was issued about 2:30 p.m., but the Sheriff’s Department said the time was about 1 p.m.

Harrell attributed the turnout to an end-of-spring-break promotion aimed at students, the hip-hop concerts at 7 and 9 p.m. and to people celebrating the end of the King trial.

The violence came in two waves. An outbreak in the area around the park during the afternoon, which began after the closing of the park’s gates, had dwindled by sundown. But violence erupted inside the park again later.

Witnesses said violence broke out at a dance club called “After Hours” when park officials closed the club when it became crowded. People outside the club broke down the door and looting took place there and at other locations inside the park, witnesses said.

The Sheriff’s Department said officials of Magic Mountain decided to close the park before the start of a second hip-hop show at 9 p.m., based on reports of looting, breaking windows and youths rampaging through the park.

Chaos broke out as the deputies tried to force the young people and other patrons out of the park, reportedly causing most of the injuries.

“People were running and being stepped on,” said County Fire Department Inspector Jack Pritchard. “They heard gunshots, or thought they heard gunshots, and started running.”

The first wave of trouble began after the park refused to allow more patrons inside. Some of the overflow crowd tried to break into the park by climbing fences, Block said. Hundreds of youths congregated on Magic Mountain Parkway between the Golden State Freeway and the park’s gates, and the Sheriff’s Department sent 300 deputies to control them.

A line of 24 deputies in riot gear marched down the hill from the park, pushing the crowd away from the park boundaries. But the crowd flowed toward a commercial strip along the freeway, where some of them stormed a Chevron station. A window was broken, and rocks and bottles were hurled at deputies, Block said. Windows also were broken at a Wendy’s restaurant and at a Marie Callender’s.

Several carloads of the youths robbed a McDonald’s restaurant, manhandling a clerk, Sheriff’s Sgt. Greg Collins said.

Steve Knipping, the manager at Marie Callender’s, said the restaurant was ransacked. “They broke windows and stole some money,” he said. “They came through so quick. They were in and out in about a minute and a half.”

Also hit in the disturbance was the Hilton Garden Inn. Windows in five first-floor rooms were broken.

Vandals dented the roofs of autos in the parking lot at the College of the Canyons by jumping on them, said sheriff’s Sgt. Bob Olmsted. Sheriff’s patrol cars roared into the area, loudspeakers bellowing: “Get out of the way, you’re going to get run over” to drive the crowd out of the parking lot.

The rap and hip-hop group TLC, which consists of three young women, has had several top 10 hits and played bills with musicians such as Bobby Brown.