You see a person lying on the ground and notice a bone protruding from the lower leg with bleeding. If the scene is safe, what should be done first?

Explanation

Once the scene is safe, first check whether the victim is conscious and breathing, as this shows whether life is in immediate danger. The open fracture and blood are obvious, but immobilizing the leg comes later, and when you call the ambulance it helps to report straight away whether the victim is conscious and breathing.