BERKELEY, Calif. — The chaos at the University of California, Berkeley, was shocking: Protesters set fires, smashed windows, hurled explosives at police and ultimately achieved their goal of canceling an appearance by right-wing provocateur Milo Yiannopoulos.

The scene gained worldwide attention not just because of the mayhem but because of where it took place. UC Berkeley is the birthplace of the free-speech movement and has been known as a bastion of tolerance.

As the university cleaned up Thursday, it struggled with questions about why the violence spun out of control and what happened to the Berkeley of the 1960s.

“It was not a proud night for this campus,” school spokesman Dan Moguluf said, later adding, “We are proud of our history … as the home of the free speech movement.”

Officials knew there was a potential for violence and went to “extraordinary lengths” to prepare for the event, Mogulof said in a statement. But school authorities say they believe the instigators were not Berkeley students.

Berkeley was the last stop on Yiannopoulos’ college tour, which had sparked protests and sporadic violence around the country. He is a vocal supporter of President Donald Trump whose comments have been criticized as racist, misogynist and anti-Muslim.

Dozens of police were called to Berkeley from nine UC campuses. The student union where the talk was scheduled was locked down hours before the event. Layers of metal barricades were erected around the building with riot police standing guard inside.

But Mogulof said what transpired Wednesday night was unprecedented.

The protests started peacefully around 4 p.m. As night fell, the crowd swelled to more than 1,500, police estimated, and “more than 100 armed individuals clad in ninja-like uniforms who utilized paramilitary tactics” infiltrated the crowd and began hurling commercial grade fireworks, Molotov cocktails, rocks and other objects at police.

They toppled the metal barricades and used them to bash windows of the student union and then set fire to a kerosene generator, sparking a blaze that burned for over an hour.

Later that night, after the crowds dispersed, a small group took the chaos off campus and into the nearby city streets of Berkeley.

Workers at several banks downtown were replacing broken windows Thursday, repairing damaged cash machines and cleaning graffiti from brick walls.

Amid the cleanup, a 21-year-old student who supports Trump was brazenly attacked on campus. The student, Jack Palkovic, was wearing a “Make America Great Again” cap as he headed to class when a white SUV slammed to a halt, and two students jumped out and pummeled him. Police arrived and arrested both men.

Only subscribers are eligible to post comments. Please subscribe or to participate in the conversation. Here’s why.

Use the form below to reset your password. When you've submitted your account email, we will send an email with a reset code.