Man killed by ‘one in a million’ gas bottle accident named

Police are reviewing CCTV footage of a "one-in-a-million" freak accident where a gas bottle fell from an inner-Sydney building before killing a man.

Married Chatswood man Hoong Leong, 37, was walking with a friend along Harrington St in The Rocks just before midnight when the 9kg bottle struck him outside the Malt Shovel Taphouse.

Police said Mr Leong, who worked for an online gaming company, had gone for after-work drinks and was on his way to Wynyard station with a colleague to get a train home.

Mr Leong was conscious and speaking after the accident.

He was taken inside the Malt Shovel Taphouse, where his condition deteriorated and he went into cardiac arrest.

Police performed CPR and rushed Mr Leong to St Vincent's Hospital where he died from his injuries.

NSW Ambulance Superintendent Kath Rallings said Mr Leong received fractures to his right arm, collapsed lungs and injuries to his hand during the "one-in-a-million" event.

"This is a freak accident and a tragedy for this man's family and friends," she said.

"He was in cardiac arrest when (paramedics) arrived at the scene.

"It's very rare for someone to survive a traumatic cardiac arrest."

Ms Rallings said the accident was triaged as a category two, which is an emergency paramedic response with no lights and sirens.

"Because the patient was said to be conscious and breathing," she said.

She did not know how long it took for the ambulance to arrive at the scene but they responded "immediately".

On Wednesday, police detective inspector David El-Badawi said that Mr Leong's friend was not doing well, and asked nearby residents to check if they were missing gas bottles.

A man who works in a building above the accident said he saw furniture fly off the roof of an apartment block during the storm.

"It was crazy - a chair flew off and hit the glass building across the road," he said.

A sign at the closest apartment building had a sign outside it warning "Cove balconies are exposed to extreme wind conditions... Items can blow off... this can pose a real threat to life and has legal recourse".

The glass building was smashed in one section on Wednesday and glass covered the path.

Brew cafe manager John Rotsos, which is nearby, said he was affected by the event.

"The poor guy, he was obviously just walking home - it's a terrible thing to happen," he said.