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BEAVER FALLS (KDKA) – The Blackhawk School District has canceled classes at Highland Middle School after they found a “questionable substance.”

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In a Facebook post, the school district said that school staff discovered the substance in the kitchen.

“In the interest of health, safety, and welfare for the students and staff, we wanted to check the air quality,” said the school district in a Facebook post. “We will take every precaution to ensure the health and safety of our students and staff.”

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During an initial investigation, the school found the substance was also located in the cafeteria. On Sunday, school officials met with a “certified air quality remediation company” to inspect the entire middle school.

“Based upon further investigation between Sunday evening and Monday night, we may be able to restart school as early as Tuesday while we contain and remediate that area,” said the school district. “This would only be considered based on the recommendations of the professionals. If the air quality concern is found to be more systemic, we may need to close Highland Middle School for a longer period of time until the remediation is complete.”

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The school district plans on having classes Tuesday pending consultation with an air quality company. All other district buildings will remain open.