A multi-million-dollar mansion has been gutted by flames after an early-morning fire broke out Wednesday.

Fire crews were called to the Bayview Avenue and York Mills Road area just after 4 a.m.

It took crews several hours to control the blaze with hot spots threatening to reignite throughout the morning.

No one occupied the home at the time but the three-alarm blaze threatened to destroy neighbouring residences.

"I came out and the whole thing was a ball of flames. Flames were shooting up to the sky and it was a frightening scene, so I gathered the family up," neighbour George Fried told CTV News.

The 6,000 square-foot mansion is estimated to be worth approximately $4 million.

The home took two years to build and construction was completed on the residence last July neighbours said.

The owners had yet to move in but did arrive on the scene after the fire was contained.

They declined to comment.

The Fire Marshal's Office is investigating but said it is too early to tell whether arson was the cause of the blaze.

Hours later, a woman was rushed to a Scarborough-area hospital after a fire broke out in the basement of her home.

Fire crews arrived at Midpines Road near Orton Park Road and Lawrence Avenue just after noon Wednesday.

The woman's 12-year-old son is being credited for saving her life after he doused his mother with water.

The woman is in serious condition after receiving severe burns to her body. Her son was also treated for smoke inhalation.

On Tuesday, three Cabbagetown homes were destroyed after a fire was set in the early hours of the morning.

The Fire Marshal's Office determined the fire was started in a garbage can near one of the residences.

Last week, seven fires were set in the Christie Pitts area.

Police continue to look for suspects in both incidents.

With a report from CTV'S Roger Petersen