CHICAGO (NewsNation Now) — Thousands of Chicago Public Schools students returned to class Monday for the first time since in-person learning was shut down in March, despite continued pushback from teachers and parents.

As the nation’s third-largest district with about 355,000 students, CPS plans a gradual return to in-person instruction after going remote due to the coronavirus pandemic. The first wave of that plan began Monday, as 6,000 pre-kindergarten and special needs students returned to class, NewsNation affiliate WGN reported.

Students in kindergarten through 8th grade have the option to return or to continue online learning, starting Feb. 1. No date has been set for high school students’ return.

“It is our city’s first day of embarking on our path to returning to in-person learning,” Mayor Lori Lightfoot said at a Southwest Side elementary school where students wore face coverings and desks had sneeze guard barriers.

The Chicago Teachers Union has opposed reopening over safety concerns, claiming the district hasn’t done enough to protect teachers from COVID-19 and has been pushing for distance learning to continue until they are vaccinated.

At Nathan Davis Elementary School in Brighton Park, teachers said every single student who had signed up to return to school actually backed out.

“We had about a dozen, between 10 and 20, students signed up for in-person learning across five classes, but every single one of those families pulled out last week,” said special education teacher Kate O’Rourke.

O’Rourke said parents pulled out their kids due to concerns about high rates of infection, as well as the difficulty of teaching young children to socialize when they’re not allowed to touch or share.

At Brentano Math and Science Academy in Logan Square, some teachers reported to the building as required, but didn’t go inside. They said they didn’t feel safe going in, so they set up tables outside.

In the meantime, thousands of students across the city saw their teachers in person for the first time in nearly a year. 

As she toured the halls of Dawes Elementary School, Mayor Lori Lightfoot said kids appeared to be “thrilled to be back in the classroom.”

Students sit at desks spaced at least six feet apart that are outfitted with safety shields. Masks are worn at all times. Signs and other symbols encourage social distancing. 

But the Chicago Teachers Union is accusing the mayor of sending mixed signals about the virus. Lightfoot extended the city’s stay-at-home order through January 22, meaning it’ll be in effect for 12 days after the first wave of students returned to in-person learning. 

Several members of the Chicago City Council also questioned CPS officials about safety and readiness in the schools Monday. 

“We should stay at home. It’s a stay-at-home advisory,” said Erin Kelley, a union member. 

But parents who have felt the strain of remote learning at home while working full-time say the CPS plan is welcome. 

CPS CEO Janice Jackson also threatened to not pay teachers who don’t show up for work, saying the phased plan is safe and will eventually bring everyone back to school.  

“It is our mission at Chicago Public Schools to bring all of our students back over the course of the next few months,” Jackson said.

Illinois logged 4,776 new confirmed and probable COVID-19 infections on Monday, along with 53 related deaths. Overall, the state has reported more than 1 million cases and 17,627 deaths.

NewsNation affiliate WGN and the Associated Press contributed to this report.