ATTLEBORO (CBS) – An Attleboro High School student who tested positive for coronavirus came to school with it Monday, the principal said, forcing 30 other students into quarantine. The student, who has not been identified, did not attend school Tuesday.

Attleboro Mayor Paul Heroux told WBZ-TV the student knowingly came to school after testing positive. “This was an egregious violation of trust one parent puts into another parent, one student to another student,” Heroux said.

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School administrators said there was not a breakdown in safety protocols.

“Monday afternoon, after school, some rumors started to circulate, someone contacted the local board of health, the local board of health started looking into it, realized that that student had tested positive and then informed us (Tuesday) morning,” Principal Bill Runey told WBZ.

Nurses reviewed seating charts in classes, cafeterias and the student’s bus to identify those who were close contacts. The 30 classmates that were considered close contacts must now quarantine for 14 days and learn remotely.

Kim Evers’ daughter, a sophomore, is one of the students quarantined. “I don’t want her to get sick because she goes down hard when she’s sick,” Evers said. “I’ve tried to calm her down but more than anything she’s worried for herself.”

Evers said the incident is frustrating. “I don’t know how often this will happen, but it happened on the first day and it kind of shakes your confidence to think it’s going to be OK,” she said.

Attleboro High School is currently in a hybrid model and undergoes a “significant cleaning” every night, according to the principal.

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Runey said it could have been a lot worse if the school had not had safety protocols in place already. Parents of all students at the high school were sent an email Tuesday informing them of the incident.

“Parents are obviously concerned about how this took place, but the majority of them are understanding of the fact that this was largely beyond our control,” Runey told WBZ.

“I didn’t expect to be able to get through this entire year without some sort of exposure and having to deal with this, so it doesn’t worry me. In fact, I think it probably heightens people’s awareness and makes then a little bit more cognizant of the fact that the actions of one can have an impact on so many.”

“We’re frantic, we’re worried,” Inette Kellam told WBZ. Her niece is a student at the high school and was there for the first day of classes Monday. “When we got the email I was like not wanting to send them back to school.”

Kellam’s niece hasn’t been told to quarantine but she doesn’t feel comfortable sending her back.

“Her brother is a real sickly boy, he has asthma real bad so I can’t afford her to bring corona home in my house.”

Runey wants everyone to work together to help keep students safe.

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“Do a little health screening at home before you come to school and certainly if you test positive quarantine right away,” he said.