Fire crews say a boy who fell more than five metres down an air intake grate at a Nanaimo high school is lucky to be alive.

Nanaimo Fire was called to Dover Bay Secondary School around 9 a.m. Thursday for reports of a fall.

Witnesses say the grate had been wide open when the boy fell in.

He suffered injures including what is believed to be a fractured or broken lower leg and was transported to hospital by paramedics.

The area was cordoned off as officials investigated the grate, which the Nanaimo-Ladysmith School District says is usually locked when not in use.

Fire crews said they’ve never responded to a call like this, and friends on site were distraught and concerned for the boy, who is believed to be around 13 years old.

The district is now investigating and says it’s unclear why the grate was open or who opened it.

“Very concerning and so we’ll do an investigation and figure out how to prevent this in the future,” said Asst. Superintendent Scott Saywell.

RCMP say they’re not investigating the incident at this time.

The fall happened on the last day of classes at Dover Secondary.

Fire officials initially said the boy apearred to fall about nine metres down the hole, but district officials later confirmed that number was closer to five metres.

With files from CTV Vancouver Island's Jessica Lepp