MENTOR, Ohio (WJW) — All school students and workers are safe following an evacuation for smoke at a middle school.

Smoke was discovered Monday morning on the second floor of Memorial Middle School, 8979 Mentor Ave., near a science classroom. The building was evacuated, according to an alert from the district just before 10:30 a.m.

“Everyone is okay,” according to a later update.

Mentor Fire Department firefighters said the smoke came from an HVAC unit whose equipment manual began to burn, according to the update.

Just before 11 a.m. Monday, the fire department had cleared the building and students and staff were returning to resume classes “per usual.”