One person has been killed and six others have been injured following a three-car crash in Sydney's south this morning.

At about 6.10am on the Princes Highway in Waterfall, the three cars collided in the southbound lanes, knocking a Mitsubishi Outlander through the guardrail, down an embankment and towards railway tracks.

The car then rolled onto its roof. 

READ MORE: Nurses caught in antisemitic tirade barred from every hospital in Australia

An investigation is under way after three cars crashed in Sydney's south this morning.

The driver of the Mitsubishi died in the crash.

He has not yet been formally identified but is believed to be aged in his 60s. 

Six other people in two other cars were taken to hospital with varying injuries.

Police are appealing for any witnesses or anybody with dashcam footage to contact Sutherland Police Station.

One of two southbound lanes was closed on the Princes Highway approaching McKell Avenue, but all lanes have now been reopened.

Check the Live Traffic website for updates.

DOWNLOAD THE 9NEWS APP: Stay across all the latest in breaking news, sport, politics and the weather via our news app and get notifications sent straight to your smartphone. Available on the Apple App Store and Google Play.

You May Also Like

Trump Orders ICE to Arrest Brick-Throwing Activists

President Donald Trump was so horrified at the violent behavior of…

Trump grants ICE new powers to do ‘whatever’s necessary’ after rock attacks during raids

President Donald Trump has directed federal law enforcement officials to use ‘whatever means…

Thieves steal Hollywood star and AFL player's documentary footage

Thieves have stolen footage for an upcoming footy documentary from homegrown Hollywood…

Chicago weather: Tornado Watch expires as severe storms move through with heavy rain | LIVE RADAR

CHICAGO (WLS) — More severe weather hit the Chicago area on Friday…