Flames engulf the Woodlands building in New Westminster on Wednesday, the fourth fire at the site in the past four days. (Amar Parmar/CBC)

The old Woodlands building in New Westminster, B.C., lay in ruins after a three-alarm blaze burned through the structure Wednesday afternoon.

New Westminster police said the blaze that broke out shortly after 12 noon was the fourth fire at the site in the past four days. Woodlands, built in 1878, was formerly part of a school for children with mental disabilities. It was closed in 1996.

'I felt like I was sitting around a camp fire. It was that strong.'— Sarah McLean, nearby resident

Wednesday's blaze prompted the evacuation of three adjoining condominium complexes in the afternoon, including 150 residents of the 72-unit Victoria Hill condo complex.

Residents of two of the complexes were allowed back home in the evening but were advised to close the windows due to the heavy smoke that was still lingering the area, the New Westminster Fire Department said.

"There’s lots of tar and paper and several layers of wall material that we don’t know what it was," Deputy Fire Chief Jim Cook said. "It was built 100 years ago so whatever they used back in the day will be producing toxic smoke."

The New Westminster Fire Department advised residents who were allowed back to their homes to close all windows because of smoke. (CBC)

Cook said the fire spread quickly and violently, and firefighters could only battle the blaze from the outside.

More than 40 members from the New Westminster and Burnaby fire departments were deployed to the scene.

"The fire is able to travel from room to room very easily. The attic space is totally wide open and the fire has managed to vent its way through the whole building," Cook said.

Sarah McLean, who lives in a high-rise building across the street from the building, said the fire was burning out of control.

"There's a big mushroom cloud of smoke. It took probably about half an hour for the flames to engulf the whole building," McLean told CBC News in a telephone interview.

"I can feel the power from the fire on my balcony.… I felt like I was sitting around a campfire. It was that strong."

Cause of latest fire not known

Sgt. Ivan Chu, a spokesman for the New Westminster Police Department, said Wednesday's blaze was the fourth fire at the Woodlands site in the past four days.

"It's hard to say whether it's a continuation or whether it's an arson," Chu said of the latest fire.

"It's an old, abandoned building. It's been broken into. People have been stealing metal from it over the years. Who knows why it's on fire," he said.

The cause of Wednesday's blaze is not yet known.