By Steven Graves

CHICAGO (CBS) — It’s becoming a familiar sight: chaos in the Loop. It happened again Saturday night with large crowds, a shooting and beatings. An officer was left with a broken arm, and police arrested more 21 young people.

Dozens flooded the streets near Millennium Park in a similar sight to last summer. A Chicago Transit Authority bus driver was beaten in the road and injured. A teenager was shot in the arm when a gunman fired after the victim bumped into him. A convenience store worker was also punched in the face.

READ MORE: Families Hold Unity Rally To Remember Loved Ones Lost To Gun Violence

Of the 21 arrested, at least one — a 15-year-old — is facing a felony battery charge.

Chicago Mayor Lori Lightfoot spoke out on what needs to change, while others have their own solutions.

“We shouldn’t have to get to that point, but if we do, we will,” she said.

Lightfoot said when the chaos erupted one tactic used by police was to push people toward trains to go home from Millennium Park where they were gathered.

READ MORE: Chicago Weather: Slightly Warmer Temperatures Before Cold Returns

Second Ward Ald. Brian Hopkins, who has worked with the Chicago Police Department on Loop crowd control in the past, said officers had intel of social media influencers organizing this as an event or flash mob. CPD would not go into deployment details, but they have had much experience responding to similar crowds as recently as July 4th weekend when officers arrested more than 60 people.

Lightfoot says the real work to fix this problem starts at home.

“These kids have to take responsibility, but I’m going to say the parents have to take responsibility,” she said. “Do you know where your kid is? Are you making sure that you’re talking to your children about how they should act in a large crowd?”

Community leader Tyrone Muhammad, who works with young Black people, took it further, saying groups like his should be a part of the solution by helping relate to kids better and diffuse situations on the ground in a different way.

“Let’s create the opportunities so our children can feel like they belong in downtown,” the founder of Ex-Cons for Community and Social Change. “Not that it’s an event to come downtown. Downtown shouldn’t be an event. It should be something that feels normal and natural because we live in this city.”

MORE NEWS: Woman Questions COVID-19 Clinic After Receiving Results Before Testing

CPD says it did work with street outreach workers to coordinate with officers, calling their response “sufficient.” Officers also recovered two replica guns and issued nine curfew violations.