Heavy smoke is billowing across the western half of Toronto this morning as firefighters battle the second major blaze in as many days at York Memorial Collegiate Institute.

Look at the smoke billowing from York Memorial Collegiate .. blanketing York/North York. #Fire #NorthYork #York pic.twitter.com/M6ZjTns4W8

— Stephanie Henry (@henrylstephanie) May 7, 2019

Toronto Fire Chief Matthew Pegg says that crews were called to the high school near Eglinton and Keele at around 3:30 a.m. on Tuesday morning, less than 12 hours after a separate fire had been put out at the same address.

"The investigation into yesterday's fire is ongoing in collaboration with the Ontario Fire Marshal and Toronto Police," said Pegg just before 7 a.m. on Tuesday. "All indications are that this fire is separate and distinct from the first fire yesterday. That investigation will continue and expand."

@Toronto_Fire is operating at the 5th alarm level at York Collegiate. Crews are battling heavy smoke and flames along with partial collapse of exterior walls. No injuries have been reported on scene. 1/2 pic.twitter.com/0yH2MuMzBB

— Matthew Pegg (@ChiefPeggTFS) May 7, 2019

More than 25 fire trucks and 100 firefighters are now working to contain what's become a five-alarm fire blaze at the school, which on Monday celebrated its 90th birthday.

Smoke from the fire at York Memorial just down the hill.

It’s a sad day for the York South-Weston community. York Memorial is 90 years old and integral part of the community both structurally and socially. #YSW pic.twitter.com/iaAtbibdeF

— Riley Peterson (@_rileypeterson) May 7, 2019

Thick, migrating smoke has prompted the evacuation of homes and businesses along the south side of Eglinton from Trethewey to Bicknell and police are urging motorists to avoid the area.

No injuries have been reported.

The initial phase of evacuation will involve those buildings fronting on the south side of Eglinton between Trethewey and Bicknell. Additional TTC buses being brought in for shelter. If you are in the area, please move east of Trethewey or west of Bicknell. @Toronto_Fire pic.twitter.com/4bJbPhMvwt

— Matthew Pegg (@ChiefPeggTFS) May 7, 2019

Damage to the structure has been described as "substantial" with several ceilings having collapsed throughout. 

Flames can still be seen shooting out from the school.

Flames are now shooting through the roof on the north side of York Memorial Collegiate facing Eglinton Avenue. Toronto Firefighters @TPFFA blasting water through front windows. pic.twitter.com/zU3cO07t4C

— Kevin Misener (@Misener680NEWS) May 7, 2019

Smoke can be seen rising from the site at 2690 Eglinton Ave. W. from many parts of the city.

Noticed this on my balcony after seeing all the tweets about York Memorial Collegiate fire. Hope everyone is safe ! pic.twitter.com/oknu4j7176

— B. Tru (@BrigitteTruong) May 7, 2019

The smell of smoke is similarly pervasive, with people as far away as Liberty Village waking up to the smell of "campfire" in their homes.

Traffic is being impacted heavily.

Fire at York Memorial extremely out of control right now - traffic is extremely heavy. Sending good vibes to all the firefighters dealing with this. ❤️ pic.twitter.com/0ANxTcHeGF

— Bella (@bellasquats) May 7, 2019

The Toronto District School Board is asking the school's students and staff to report to George Harvey CI "at the usual time today" on account of the fire.

Both Monday's fire and the ongoing blaze at York Memorial are still under investigation. Only the former has been declared "suspicious" by police thus far.