[...]
Police contained the crowd for most of the night by targeting and arresting disorderly individuals, Wibert said.

But at about 1:30 a.m., police declared the event an unlawful assembly and ordered the crowd to disperse after a change in its mood.

After numerous loudspeaker commands to disperse were ignored by some partygoers, police launched smoke grenades and flash bangs — which produce firecracker-like noise and light — into the crowd at about 2:07 a.m.

Wibert said the warnings only eliminated some of the crowd.

Some students reported not hearing the loudspeaker announcements, while others said they heard them but didn’t take them seriously.

“I never really saw a warning,” junior Tony Smith said.

“I’m sure they did somehow, but I never saw.”

At about 2:16 a.m., officers launched tear gas as what Wibert called a last resort.
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