Nearly 24 hours after smoke was first seen billowing from an industrial building in north Cambridge, fire crews remained at the scene.

Firefighters were first called to the building on Sheffield Street around 2 p.m. Monday.

Sheffield Fire aftermath

The building was not occupied at the time of the fire. It was being used to store various automotive parts, including rubber and plastic materials.

According to Cambridge fire chief Neil Main, some chemicals stored in the building were not affected by the fire.

Around 5 p.m. Monday, the building’s roof collapsed, trapping debris underneath.

While the fire has been under control since around that time, hotspots continued to persist – which is why crews remained at the scene as of early Tuesday afternoon.

Environmental crews were also called in to monitor air quality and prevent water used to fight the fire from contaminating the nearby Speed River.

A shelter-in-place order was issued for homes, school and businesses in the area, with people being advised to stay inside and keep doors and windows closed.

By Tuesday morning, officials were saying that air quality was sufficient for people to take part in normal outdoor activities if they did not notice any possible symptoms.

Officials warned that the smell from the fire – which was strong enough to prompt several calls to the fire department in Guelph, 15 kilometres away – could linger in the air for several days.

The fire is not considered to be suspicious, although its exact cause remains under investigation. Damage is estimated at $1 million.

With reporting by Krista Simpson