London firefighters battled a blaze at in the central east area of the city on Tuesday morning.
Crews were called to 40 Balmoral Ave., near Oxford and Adelaide streets, just before 7 a.m.
There was extensive damage to the roof and flames were visible as CTV news arrived at the single-story home.
London fire Insp. Jack Burt says, "Our crews did have to go in and do search and rescue, primary search, secondary search to confirm nobody was in the home at the time of the fire."
The woman who lives there was not home, but there were animals there and despite firefighters' best efforts - including performing CPR - two cats died in the fire.
An investigator was on scene for most of the day, and it's believed the fire started either in the kitchen or in the attic.
An official with the Electrical Safety Authority was also on site Tuesday.
While the cause remains under investigation, damage is estimated at $80,000. It's also unclear if the home can be salvaged.
Officials say the fire trucks had a hard time getting to the fire due to the condition of the street, but it wasn't a significant delay, with Burt saying they were there in under five minutes.
