NORTH HOLLYWOOD  (CBSLA)  — The principal of Lankershim Elementary School in Highland left her post after someone left her some racially-charged mail. And it was the third time it happened.

Crecia Sims is black.

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KCAL9’s Nicole Comstock spoke to students  who don’t quite understand why Mrs. Sims is gone.

Adaiyah, a third grader, says simply, “She was nice.” Adaiyah also thought Mrs. Sims was doing a bang up job.

“She took care of problems,” Adaiyah says.

The third grader knows she won’t see Mrs. Sims again.

“It’s sad,” she says.

Many adults would agree. They’re also having trouble wrapping their heads around what happened. Sims decided to leave the school this week, specifically Tuesday, when she found a racially-charged letter in her mailbox.

“Whoever wrote this is a coward,” said  Dr Dale Marsden, superintendent of the San Bernardino City Unified School District.

At a meeting this evening, the San Bernardino City Unified School District said they believed the author of the letter was an employee of the school — only employees have access to that particular part of the building.

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For Sims, the third letter — her third in her three years at the school — was a signal to leave.

“Within days of her being here,” says Marsden, “she received a threat of a racial nature.”

The first letter came three years ago after she held a staff meeting. It said, “Thanks for the collaboration, [N-word].” A second racially-charged letter showed up a few months later and then nothing — until this week.

“If you wanna be evil, there’s a lot of other places you can go to be evil and comfortable. But ours school is not that place,” said School Board member DannyTillman.

He told parents that if they didn’t feel their students were safe at Lankershim Elementary any more that he understood and would help facilitate their move to another campus.

“I honestly don’t know if I want to keep her here,” said parent Crystal de la Cruz.

She told Comstock that she worries that someone could be passing that kind of racism on to student.

“This person could be smiling in my face, talking to her,” says de la Cruz.

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“And it’s scary to know that someone in the school,  could be teaching my kids?,” says Veronica Audelo, a recreational aide.