Fire crews were on the scene at Burnaby Central Secondary on Friday, after a smoke bomb was apparently set off.
"The kids don't want to be in school this time of year," said acting assistant fire chief Darcy O'Shea, with a laugh. "Whatever it was, it wasn't very serious in terms of an emergency or any fire or any health hazard."
According to O'Shea, there was a similar incident on Thursday at Burnaby South Secondary.
"There wasn't much to that one either," he said. "It was quite smoky in the hallway. We had to do some ventilation. ... Fire alarms were set off, there was quite a lot of smoke on the second floor. A smoke bomb had been activated in the stairwell."
A couple of trucks stayed on the scene while the school was ventilated.
"It's not uncommon this time of year," O'Shea said.
"Any time that someone does something like that, ... when we are sending six fire trucks down the road ... it prevents us from having a more timely response to a real emergency," he added.
