Vancouver firefighters spent hours working to extinguish a three-alarm blaze that broke out at a house for sale in Kitsilano Thursday afternoon.

Flames broke out at the three-storey home on MacDonald Street at West 3rd Avenue at about 1:30 p.m.

Firefighters said they'd entered the home to do a primary search and found no one inside, but they had to leave the interior when it was determined the house was not structurally sound. Instead, they transitioned into defensive mode, battling the blaze from outside.

"We haven't been able to make entry to complete a more thorough secondary search, so we're not confident at this time in saying that everyone is out," Vancouver Fire's Jonathan Gormick said.

Crews were still on scene hours after the fire was sparked, though it was brought mostly under control by 5 p.m. Officials expected to be on the scene a few more hours, dousing hot spots and searching the damaged property.

He said crews also concentrated their efforts on keeping the flames from spreading, but that those who lived next door are "extremely lucky.

"It was only the fast actions of the first-arriving crew who pulled a hose line immediately and began to cool it that saved it. These houses are very close together, wood framed, and it wouldn't have taken much for it to spread to the neighbouring house."

From the street in front of the home, flames could be seen coming off the roof as firefighters protected the house just a few feet away.

A woman who lives in the house next door said almost immediately after arriving, firefighters created what she described as a wall of water between the homes.

"I could see flames shooting out of the roof towards our house, and I heard that there was an explosion," Julie Bergeron said.

She said she was in total shock, "shaking like a little leaf," in the hours following the fire, but she's thankful the situation wasn't worse.

"I'm so grateful to have everybody out safe and knowing that (firefighters are) there to take care of the fire… They are amazing. They're so focused, they know what they're doing, they communicate with each other," she said.

There appeared to be some damage to her building's roof, but it seemed like they'd been able to stop the spread.

The home that caught fire has been up for sale for some time, neighbours told CTV News. One neighbour said they thought someone was in the home at the time of the fire, possibly a short-term renter.

While the owners wait for a new buyer they've been renting it out on Airbnb, several residents of the area told CTV.

"It's different people every week. It's been like that for a few months," Bergeron said.

An Airbnb page with photos matching a real estate listing describes the home as a two-bedroom, two-bath duplex that can fit eight guests. Listed at $325 a night, the home has a private two-level suite, and the owners live in a separate section, the listing suggests.

The home appears to be for sale for an asking price of $2.588 million. The real estate listing says the 3,144-square-foot house is divided into three suites: the one listed on Airbnb, a one bedroom and den, and a two-bedroom unit on the ground floor.

The realtor claims the home has a potential gross income of $84,000 a year if the would-be owner opted to rent the suites.

MacDonald Street was closed between Cornwall and West 4th as crews doused the flames. The immediate area was "extremely smoky," firefighters wrote in a message asking the public to avoid the scene.

The cause of the fire is not yet known, and an estimate of damage has not been provided.

With files from CTV Vancouver's Shelley Moore, Christian Adler and Ben Miljure