Woman critical after Sydney car crash

A woman has been airlifted to hospital after a multi-vehicle accident in Sydney's southwest.

A woman is fighting for her life and a child is hurt after a three-car collision in Sydney's southwest.

The woman was airlifted to Liverpool Hospital in a critical condition after colliding head on with another car, injuring another woman and her five-year-old son in the accident at Austral on Monday morning.

The boy was taken to Westmead Children's Hospital while a third driver and her 12-year-old son escaped injury.