The breakthrough came after nearly a week of canceled classes for CPS.
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CTU suspended its remote work action after a House of Delegates vote while its members vote on a deal with CPS.
The union's 700-member governing body voted 63% to 27% in favor of ending the remote work action that affected about 300,000 students.
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"I'm ultimately proud the Chicago Teachers Union took a stand," CTU President Jesse Sharkey said. "We're going to keep doing what's right as we navigate this. It's not a perfect agreement but we'll hold our heads up high, as it was hard to get."
Lightfoot said Monday night that teachers will be back in classrooms Tuesday, and students will return to school on Wednesday. Classes are still canceled for students on Tuesday as teachers prepare to return to work.
Janet Luszczki is relieved her 12-year-old son is heading back to school tomorrow, and so is he.
"Both sides came to the agreement, the right agreement. The kids need to be back in school. The teachers need to be back in school," she said.
Luszczki said the disruption prompted her to hire a tutor for her son and she was forced to lean on family members for child care.
Neither the union nor CPS put families first in the dispute.
"Kids come first," she said. "The adults have to think about the kids, and politics shouldn't enter."
CPS released a statement on the CTU vote, saying: "Once the Chicago Teachers Union (CTU) votes to ratify the new agreement, Chicago Public Schools (CPS) will promptly share with our staff, families, and community the details and the timeline for implementation of related new policies and procedures. That union vote is scheduled to take place from 3 p.m. today until 4 p.m. tomorrow, Wednesday, Jan. 12. We are excited to welcome back to school buildings all our students, teachers and other members tomorrow morning."
And while rank and file members are voting on the proposed agreement now, agreement doesn't mean harmony.
"You know, I'm still struck by the tone deafness of our administration," said CTU Vice President Stacy Davis Gates. "Our mayor is not a partner."
"Parents are going to be wondering when the next battle is going to ensue. This has been a long time pattern," said ABC7 political analyst Laura Washington. "What you're going to see is many more parents start to look at alternatives. They're going to start to move out of the system. That's already been happening. I think it's going to happen even more. Parents just don't feel they can rely on CPS any longer."
Some students at Henry Nash Elementary will remain in quarantine following an outbreak of COVID cases.
According to State Rep. LaShawn Ford, in whose district the school is located, 10% of the nearly 225 students are vaccinated.
"There's obviously a failure," Ford said.
The lawmaker and his supporters in the community are using the grade school's quarantine status to push for more resources to be allocated to the city's West Side. Austin is listed in the top 15 most vulnerable communities according to Chicago's COVID-19 vulnerability index.
Teachers and staff slowly trickled into Ogden Elementary School Tuesday morning to prepare for in-person learning after five days of no instruction.
Elizabeth Cilley brought her son into school at Ogden elementary Tuesday.
A small group of kids are allowed back inside, and she is relieved students are coming back Wednesday.
"It's such a hard time for everybody, and these children are suffering," Cilley said. "I mean we are in a position, I feel very lucky that I have flexibility, and my son's father has flexibility to stay with him, but there are so many families in the CPS system that did not have access, so those children are cold and without food. I think this is, it felt very neglectful. I am happy we can be here; it's good for them."
Among the highlights of the deal is an agreement to expand testing of students, but not the opt-out testing program the CTU had sought. CPS did agree to a set of metrics that would trigger a move to remote learning for individual schools, but not a district-wide metric as the union had wanted.
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The deal also includes expanded PPE and efforts to increase testing consents for students, Mayor Lightfoot said.
The mayor said there will also be new incentives to increase the number of substitutes in the district. She said the full details of the deal will be released after the agreement is ratified by the full CTU membership.
CPS CEO Pedro Martinez said the district remains committed to the safety of teachers, staff and students. The agreement proposed extends through the end of summer school, Lightfoot said.
"Some will ask who won and who lost," Mayor Lightfoot said. "No one wins when our students are out of the place where they can learn the best and where they're safest. After being out of school for four days in a row, I'm sure many students will be excited to get back in the classroom with their teachers and peers. And their parents and guardians can now breathe a much-deserved sigh of relief."
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"I want to make sure that everybody knows that we are committed to the safety of our students. We're committed to the safety of our staff. We're going to work together," Martinez said. "There's some really good things in this agreement."
Tuesday marked the fifth straight day most CPS students have been out of class.