Police are at the scene of a serious crash at Port Noarlunga South.
Just before 5pm Tuesday 24 November emergency services were called to Cliff Avenue near Commercial Road after reports of a collision between a motorbike and a 4WD.
The motorcycle rider initially got up and walked to Commercial Road where he collapsed and is now in a critical condition.
Commercial Road is closed to north bound traffic and motorists are being diverted. Please avoid the area and find an alternate route.