It’s been less than three months since school started and more than a third of Medard H. Nelson Charter School’s teachers have quit.

Seven of the 20 teachers at the New Beginnings network school have resigned, in addition to the principal departing.

Though parents didn’t know that number when they gathered Thursday night, they knew teachers were leaving — and often heard it first from their children. About 500 children attend the school.

New Beginnings CEO Sametta Brown confirmed the number of resignations Friday after The Lens asked Thursday night. Of the seven teacher who resigned, four left before the principal, and three after, Brown said.

Zoneke Domino-Thomas is the mother of two Nelson students and the president of the school’s parent-teacher organization. She invited Brown to a meeting Thursday to answer questions for frustrated parents after the school’s principal departed without notice earlier this month.

Principal Deidra Bradley was dismissed on Oct. 17. Parents weren’t notified until one week later — in a letter dated Oct. 24, the same day The Lens inquired about Bradley’s employment.

More than 30 parents and teachers gather in Nelson’s charged cafeteria Thursday night. For more than 90 minutes Brown listened to parents concerns and answered some questions.

“I think we’re all upset because our children knew before we knew,” Domino-Thomas said.

Brown told parents Bradley’s departure was part of a necessary reorganization and did not disclose any details.

She didn’t have many direct questions to answer as parents poured out concerns and frustrations. Worries ranged from the security of the building to the academic rigor offered by substitute teachers to the cancellation of activities.

“We’re bringing teachers from our other schools,” Brown told parents, addressing the teacher resignations.

Nelson is one of four charter schools overseen by the New Beginnings network. On Friday, Brown told The Lens two teachers from each of the network’s other three schools were now stationed at Nelson, though it is unclear what roles they are in.

On Thursday night, Brown told parents that teachers who left had disrespected children and families by not giving two weeks notice.

Domino-Thomas said she didn’t feel much better after the meeting and was frustrated by Brown’s “vague answers.”

“We are still at a loss because we need an action plan.”