The Seattle School District says they have a clean-up plan and they won't have to close classrooms. But some parents are upset.

The mold was found in the ceiling tiles of three classrooms and a stairwell inside the school in September. District officials say it came from a leaky roof. They've already done testing and say air quality hasn't been affected.

"The problem as we know it has been encapsulated," said Patty Spencer with the Seattle School District. "We have an aggressive plan to fix the problem. Some of it will be done over winter break. We then are going to go in, probably over the summer and investigate tiles throughout the building."

But at least one parent isn't so sure that will work.

"I'm not agreeing to that," said parent Jennifer Aspelund. "Because I have not read anywhere where encapsulating the mold makes it safe where you can deal with it. The deal is it's immediate remediation."

About 1,100 students attend Nathan Hale. The building was built back in the 1960's.