A Sydney restaurant has been destroyed by a suspicious fire in a building that came under scrutiny for its safety standards after a student leapt to her death during a blaze in 2012.

Rashays in Bankstown was destroyed by the fire that started just after 3am on Thursday.

More than 200 people from the apartment complex had to be evacuated as the West Terrace pizza and pasta restaurant went up in flames. The building was the scene of a fatal blaze in 2012 when a student leapt to her death after being trapped on a balcony.

Fire investigators brought in sniffer dogs on Thursday to detect accelerant. AAP understands there was an explosion moments before the restaurant was engulfed.

Whether the audible warning system was activated to alert residents is also part of the investigation after reports some didn’t hear it, Fire Rescue NSW Superintendent Ian Krimmer said.

There’s also concern some residents may have ignored the warnings after a heat detector malfunctioned causing a false alarm earlier in the night.

A staff member who lives in the building is believed to have gone door to door waking residents and helping them flee the burning building.

It’s not the first time the Bankstown restaurant, one of 16 in the NSW chain, has been targeted by arsonists.

In 2012 the restaurant, which was then company owned and in a different building, was destroyed in a suspicious fire.

It only re-opened at the new location about 18 months ago as a franchisee-owned restaurant employing about 30 locals who are now without work.

Rashays spokesman Brendon Ford said there was no reason to think someone wanted to target the restaurant chain.

‘It is disappointing. We don’t see it as someone particularly targeting the brand and we’re really wanting to find out what the outcome of the police investigation is before we draw any real conclusions to what has happened and how it’s happened,’ he told reporters.

He said the restaurant owner was thankful no one had been hurt in the fire, though one person was taken to hospital as precaution after smoke made its way through several levels of the building.

Fire safety measures in the West Terrace building were the subject of a coronial inquest last year after Chinese student, Connie Zhang and her friend, Ginger Jiang, were forced out of a window in their fifth-floor apartment because of a fire.

Ms Zhang, 21, died on impact, while Ms Jiang is wheelchair-bound.

Last year’s inquest found Ms Zhang may not have died if the complex had a sprinkler system, though the building was 10cm short of the 25-metre threshold that required it.

‘Fire Rescue NSW for a long time has asked for the installation of sprinklers in residential buildings such as this,’ Supt Krimmer said, adding the West Terrace building did comply with current standards.