The esplanade, already crowded with its usual population of bikers and low-riders, had swelled to 2000 people gathered for a long-planned concert. The music began at 6 p.m., and was scheduled to continue for three hours as specified by city permit.
Around 8 p.m., half a dozen patrol cars appeared and parked opposite the beach. A member of the last band scheduled to play crossed the street to ask the police if it was okay to perform. A sergeant told him to go ahead. As the band fired up its amps, police began to hassle spectators on the periphery of the crowd for drinking in public.
Somebody, allegedly a biker, strolled up to one of the unattended police cars, emptied a bottle of gasoline in the back seat, and threw in a lighted match. The police, understandably, took offense.
The fire was quickly doused. Police officers began opening up their car trunks and taking out riot gear. Being focused on the band, few in the crowd were aware of what was coming down. Even fewer heard the police loudspeaker when it barked, "This is an illegal gathering. You have one minute to disperse."
Almost immediately, the air filled with a pungent, nauseating gas - not ordinary tear gas, but the CS type, which sickened its victims. With clubs swinging, the police waded into the crowd, which was trapped against Elliott Bay. Some fought back with fists and rocks. Police cars were damaged.
Grenade after grenade exploded along the whole length of Alki Beach. A brisk evening breeze carried the fumes inland, choking families in neighboring homes as they watched TV or ate a late Sunday dinner. One grenade rolled into a small grocery, gassing the owners, their infant child, and several customers.
The police eventually cordoned off the strip and arrested six partygoers for rock-throwing or public drinking. The following day, Police Chief Frank Ramon (who was trying to get out of town on vacation), defended his men against complaints of over-reaction and excessive force. He hinted at the notion of a planned provocation since "most people don't ordinarily carry firebombs to a concert." He explained that tear gas was the "best alternative" in such a situation.
Ramon didn't convince very many listeners, particularly reporters, as eyewitness reports piled up. The official story of why the police had descended on a legal concert in the first place changed from noise complaints to reports of windows being broken, none of which was verified. Many suspected that the police had, by their own presence and actions, precipitated all that followed.