Residents in a Walkerville neighbourhood are being told to remain indoors and keep their windows closed through the night as firefighters remain on the scene of a massive fire.

Crews were called after 11 a.m. Wednesday to a warehouse formerly operated by Gel Tech near Argyle Rd. and Ottawa St.

“Upon arrival crews found heavy smoke,” says chief fire prevention officer John Lee. “Conditions on the first floor were puffing out the roof.”

Plumes of black smoke could be seen for miles and emergency officials first told residents during the noon hour to close their windows and doors and to stay indoors.

Lee says they confirmed early in the afternoon that the fumes were not toxic, but they continued the order for residents as a precaution.

A voluntary evacuation was also declared for residents from Ottawa St. to Shepherd St. and Argyle Rd. to Kildare Rd. The city offered the Gino Marcus Community Centre as a place for residents to stay in the interim.

The Market Square, Shoppers Drug Mart and a bingo building nearby were all evacuated as a precaution, as dozens of onlookers watched crews fight the fire.

“I don’t think I’ve ever seen a fire this bad in Windsor, ever,” said one man.

No injuries have been reported due to the fire.

Firefighters first battled the blaze from inside of the building, but were forced to move outdoors because of heavy smoke.

Four aerial trucks were used in total to help crews battle the stubborn blaze from above.

“We called in additional staff to man other trucks, standby other stations,” says Lee.

Lee tells CTV News there was a partial roof collapse around 3 p.m. that reignited the blaze, so heavy equipment was brought in to dismantle the building to help extinguish the flames.

While the offices in the building are vacant, there is no word what else could be in the warehouse.

There’s no word yet on what caused the fire.

There is also no damage estimate, but it’s expected to be a significant amount.

The City of Windsor Police and Fire Joint Emergency Command is expected to remain on scene through the night.