The first week of school was supposed to mark a triumphant return to classrooms at San Francisco’s Everett Middle School after more than a year of distance learning.

But as computer science teacher Yesi Castro-Mitchell welcomed a class of sixth graders last fall, a student started punching her, again and again.

Castro-Mitchell wrapped her arms around her head and hoped for the blows to stop. She remembers the stunned silence in her classroom as other students witnessed the assault. The teacher suffered a concussion, a dislocated jaw, chipped teeth and hearing loss in her left ear that now requires a hearing aid.