Quick action by another worker saved the life of a man who had his leg torn off at a construction site at Wolli Creek in Sydney’s south today.

A CareFlight specialist trauma doctor said the worker took off his belt and used it as a tourniquet to stop the injured man from bleeding to death as emergency services rushed to the Marsh Street site shortly after 2pm.

The doctor said the action in applying the belt to the stump of the man’s right leg was a brilliant act of improvised life-saving.

CareFlight landed in an adjacent park to allow the crew trauma doctor to team with ambulance paramedics treating the man.

The CareFlight doctor said the 28-year-old man apparently was caught under a large excavator.

The doctor administered emergency blood transfusions before continuing treatment with the ambulance paramedics as the man was taken in a road ambulance St George Hospital.

The man remained in a serious but stable condition on arrival at the hospital.