Police are investigating a serious crash at Willunga Hill this morning.

About 8.30am on Friday 16 February, police were called to the intersection of Pages Flat Road and Victor Harbor Road after a Mazda SUV and Toyota sedan collided.

The Mazda driver, a 73-year-old man from Port Elliot sustained serious injuries in the crash and was flown to the Royal Adelaide Hospital in a critical condition.

The driver of the Corolla, a 79-year-old Yankalilla woman, and her three female passengers aged 69, 74 and 88 sustained non-life threatening injuries and were all taken to the Flinders Medical Centre for treatment.

Major Crash Investigators attended to examine the circumstances surrounding the crash.

Traffic on Victor Harbor Road and Pages Flat Road were diverted for several hours but roads were reopened just before 3pm.

Anyone who witnessed the crash and hasn’t yet spoken with police is asked to contact Crime Stoppers on 1800 333 000 or online at https://crimestopperssa.com.au