The black and white UNITY mural greets students, staff and visitors at City High School in downtown Tucson.
Forming that complete whole is foundational to what City High, a public charter school, was founded on in 2004, teachers say.
On Thursday, staff and teachers brought that message of community full circle — announcing to their board that they will form a union — at the CITY Center for Collaborative Learning, a nonprofit that includes City High and two middle schools: Paulo Freire Freedom School, University and Downtown campuses…