Students are back in classrooms following a smoke scare today on the Palo Alto High School campus.

Assistant Principal Erik Olah confirmed that the fire, first reported around 1 p.m., was caused by a mechanical failure.

“There was some sort of faulty HVAC system within the English building that caused some sort of small fire,” Olah said.

Students were sent back to classrooms after 15 minutes, but Olah said administrators will investigate further issues if they arise.

“We will have to look into the system and figure out if it’s an ongoing issue or something that was a one-time situation, but we will get it cleared away,” Olah said. “The fact that we’re sending students back now means that it’s not going to be an issue going forward, but if there’s something that needs to be fixed, we’ll fix it.”

English teacher Joshua Knowles-Hinrichs, who was advising a club meeting in the building, was the first person who smelled the smoke.

“We were in the middle of the YCS [Youth Community Service] meeting in 215 … and basically some students who were sitting up against the wall opposite the door started to smell smoke and burnt plastic and called me over,” Knowles-Hinrichs said. “I smelled it as well and then I went around the building into the book room cause that’s what’s on the other side of the wall they were sitting next to and when I went into that room it smelled really strongly of burnt plastic, but there was no smoke. I called admin and I called 911 right away, which is the procedure.”

Knowles-Hinrichs said some teaching content may have to be moved to next week, but the safety of students is the top priority.

“Safety is so much more important [than lessons] and just getting people out of the room so that they’re not even breathing it [the smoke],” Knowles-Hinrichs said.

Additional reporting for this story provided by Jonathan Chen and Benjamin Grimes.