Two seriously injured in drink driver crash in Waterfall

Police are investigating a crash that left a man and woman with serious injuries at Waterfall Sunday morning after their car was hit from behind by an alleged drink driver.

Just before 1am, a silver-coloured Mazda 2 driven by a 22-year-old woman, crashed into the rear of a maroon Ford Laser travelling south on the Princes Highway.

The Ford Laser then left the roadway and hit a tree, and came to rest in a culvert near the shoulder of the roadway.

A woman and a man travelling in the Ford Laser were trapped in the car for a short time before being released by emergency services.

All were treated at the scene by NSW Ambulance Paramedics before the man was flown by rescue helicopter to St George Hospital in a serious condition.

The woman passenger in the Ford Laser was taken to St George Hospital by ambulance where she remains in a critical condition.

The driver of the Mazda 2 was not injured during the crash. She underwent a roadside breath test which produced a positive reading.

She was arrested and conveyed to Sutherland Police Station for the purpose of a breath analysis where she allegedly returned a reading of 0.090. She has also been taken to Sutherland Hospital for mandatory blood and urine testing.

Police from Sutherland Local Area Command attended and established a crime scene, and southbound traffic on the Princes Highway is being diverted by contra flow for several hours as investigations take place.

Specialist crash investigation officers are investigating the incident and are urging anyone with information to contact Sutherland Police Station or Crime Stoppers.