A 43-year-old builder is in a serious condition after falling three metres and landing on his head at a construction site in Bellevue Hill this morning.

A specialist medical helicopter team landed at Lough Playing Fields on Manning Rd prior to responding to Rivers St in Bellevue Hill.

Emergency services have shut down Old South Head Rd in Bellevue Hill after a high pressure gas main ruptured.

A short time ago, the main flow of gas had been closed off, however emergency works continue to make the area safe.

A man has been stabbed in the face and arms multiple times during a vicious assault at Pyrmont overnight.

At around 10.50pm police responded to the intersection of Pyrmont Bridge Road and Wattle Streets after receiving reports of an assault.

A man in his twenties has been transported to hospital after a crash between a car and motorcycle in Bondi Junction this evening.

The collision occurred just after 7.00pm on Bondi Rd near the intersection of Flood St.

Sydney Water and a host of contractors continue to work on a sink hole and water main rupture in Bay St Double Bay.

At 5.30am a water main ruptured under the road. A truck drove across this rupture and the front wheels of the vehciel entered the sink hole.

A 55-year-old female was struck by the side mirror of a private bus on Alison Rd, Kensington this evening.

This follows a separate crash between two Government buses in Kensington.

Two government buses have collided in a crash on Anzac Parade, Kensington late this afternoon.

Five patients were treated on scene by NSW Ambulance and three were transported to hospital.