Jefferson Airplane’s legacy may be intertwined with peace, love and the hippie counterculture, but the vibes were far from serene on Aug. 21, 1972, during the group’s performance at the Rubber Bowl in Akron, Ohio.

A crowd of roughly 20,000 fans filled the stadium that day, but the trouble started among the hundreds more who were outside the venue, watching the show for free from a hill that overlooked it all. As day turned to night, fans without tickets – many of whom had been drinking or taking drugs – became restless and began harassing police officers who were serving as concert security.

“We were getting pummeled with rocks and bottles and stones and whatever else they could throw,” John Cunningham, who was a lieutenant in 1972, recalled to the Akron Beacon Journal. Police responded to the rowdy fans by shooting canisters of tear gas.

“Before you know it, just all hell broke out,” added one concertgoer who watched the mayhem build. “It was a small war zone, let me tell you. There was cops and teenagers just going at it everywhere. Fistfighting, throwing rocks, anything that people could get their hands on to throw.”

Inside the stadium, Jefferson Airplane added to the chaos. From the stage, singer Grace Slick encouraged those rebelling against the police, reportedly shouting things like “get the pigs” and “fight the establishment.”

“[The police] knew we remembered Kent State and they didn’t trust us,” Slick recalled of that night in her autobiography, Somebody to Love? “All along the front of the stage stood a row of 25 officers, arms linked in riot style, creating a barrier. Their heads covered with bulletproof visors, their hips loaded with clubs and guns, they formed a line between the audience and us like a bizarre group of armored, hairy chorus girls.”

The unrest continued until roughly 11:30 p.m. when a bomb threat was called into the Rubber Bowl office. Police shut down the show, further angering the crowd.

As fists and projectiles continued to be thrown, members of Jefferson Airplane got involved as well. Chick Casady, the band’s equipment manager and brother of bassist Jack Casady, intervened when police were getting rough with a fan.

“I saw them mace Chick, so I went over and objected to their treatment of my friend,” Slick remembered. “They maced me. Paul [Kantner, the band’s guitarist and singer] came over to object to their treatment of me. They maced Paul. The three of us were escorted to jail where bail was set and the attorneys were called to rectify the situation.” In total, 25 fans were arrested that night, nine officers were injured and 12 police cars were damaged in the melee.

Slick, Kantner and Casady were charged with assaulting an officer but eventually pleaded guilty to a lesser charge. The trio paid a small fine and promised to be on their best behavior whenever visiting Ohio. Decades later, Slick admitted she and her bandmates never felt comfortable with authorities, especially the police. “I don’t know why, but any time I saw a badge, something in me would snap,” the singer confessed. “All I could see was some goof who took smelly shits just like everyone else, having the unfair advantage of firepower.”