One man has died and a teenager is fighting for life after winds reaching up to 93km/h smashed through multiple western Sydney construction sites, trapping a tradesman under a brick wall.
Construction workers dug through rubble at the Carlingford site to find their trapped colleague as emergency crews rushed to the scene.
They said the wall, which was under construction, was "blown over in the wind".
Paramedics performed CPR on the 30-year-old after he went into cardiac arrest, a NSW Ambulance spokesman confirmed.
His injuries were too severe and he died soon after.
In a separate incident at Kellyville, about 20km away, paramedics treated a young man for significant head and facial injuries after he too was hit by a collapsing wall.
The 19-year-old was taken to Westmead Hospital in a critical condition.
"It's understood the construction worker was pulled unconscious by co-workers from underneath the pile of bricks which collapsed during highly windy conditions," authorities said.
At Kellyville: male construction worker, 19, treated for critical head injuries after brick wall collapse. Taken by rd to Westmead Hospital pic.twitter.com/AfcDQ9RoPr— CareFlight (@MyCareFlight) August 16, 2017
SafeWork NSW has sent inspectors to both sites.
The Bureau of Meterology this morning recorded winds reaching 93 km/h at Prospect Dam in Sydney's west.