Several homes on a west-end street were evacuated on Sunday night as Toronto Fire crews battled a 4-alarm house fire.

Crews were called to 181 Osler Street near the intersection of Davenport Road and Old Weston Road, just after 7:00pm Sunday.

Fire captain Adrian Ratushniak says they found heavy smoke pouring out of the home and crews later found that the flames had spread to three adjoining row-houses and smoke damage was sustained to one more home. It went up to 4-alarms, but at one point crews thought it could become a 5-alarm fire.

Toronto Fire officials say as many as 18 fire trucks and around 80 firefighters were on the scene by 9:30pm.

Authorities believe the blaze started in the basement of the century-old home and travelled through the walls and into the attic, where the fire spread to the house next door.

Toronto Fire says the home that the fire started in is a write-off and it is too early to determine what sparked the flames.

Captain Ratushniak says one person was taken to hospital for smoke inhalation but they may have had an underlying medical condition.