Parents at a Maryland elementary school are shocked not only because racist graffiti was found scrawled on one of the walls but also because the school waited so long to tell the parents.

A student at Sligo Creek Elementary School in Silver Spring, Maryland, reportedly found the graffiti, which said, “KILL KILL KILL BLACKS,” and reported it to a teacher, though the teacher apparently did not tell the school administration.

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The graffiti was instead discovered after someone on the service crew for the building found and reported it to the administration. The cleaning crew scrubbed off the graffiti, and the administration told parents about the incident on Monday, but many are saying that the school waited too long.

“It’s disturbing,” Sean Gowen, a parent at the school, told NBC Washington 4. “We should have known about this a lot sooner.”

“It is shocking,” said resident Sybile Bayiha. “The teacher should have reported it and the kids should learn better.”