Australia: Sydney building engulfed by major fire (VIDEO)

A large fire engulfed a seven-story building in Sydney, Australia, on Thursday, causing parts of the structure to collapse and sweeping smoke and ash around the city.

Authorities said more than 50 people were evacuated from the area close to the city's Central Station.

More than 120 firefighters and 35 fire trucks have been deployed to contain the blaze.

Fire and Rescue NSW — referring to the state of New South Wales — said the building inferno initially spread to neighboring buildings, including residential apartments.

"The fire is now effectively contained but it will be a very substantial and prolonged duration of firefighting to extinguish the fire completely," Deputy Commissioner Jeremy Fewtrell said.

One firefighter was treated by paramedics for a burn to his arm but there were no reports of injuries.

Unoccupied building was planned hotel

The building in Sydney's Surry Hills district was an old hat factory that was planned to be converted into a hotel, according to a recent development application lodged with city authorities.

"All you could feel when standing here was heat on your face from the flames," one witness told public broadcaster ABC News.

"And when they started to move us back, a car just in front of the building caught fire."