The arson unit is investigating a blaze that destroyed portable classrooms at Stanley Knowles School on King Edward Street on Wednesday morning.

Damage is estimated at $750,000.

Crews were called around 1:30 a.m. Wednesday and arrived to find three portable classrooms ablaze.

Officials say the portable structures are a total loss, but crews were able to stop the fire from spreading to the main building of the school.

The school's principal, John Dryzstek, says that the school will open next week.

Dryzstek says, however, that the fire complicates things for the first day back.

"We do need the space. Our school is very crowded and we have more then 1,000 students and we have no vacant space anywhere in the school," he said.

The portable classrooms burned in the fire were previously used for French, music and daycare. Staff members are now examining other options.

Dryzstek says the school also lost supplies that were stored in the classrooms.

"All of that has to be replaced. One of the rooms was elementary music--there were instruments in there and technology in each room," he said.

While the school's main building did not sustain fire damage, there is an odour of smoke inside. Dryzstek said crews are already working on removing the smell so staff and students with allergies will not be affected next week.

Anyone with information on the fire is asked to contact the arson unit at 986-6813, or Crime Stoppers at 786-8477.

- with a report from CTV's Jillian Taylor