If you suspect a crash victim has a broken bone in their leg, what first aid should you provide?

1. Try to pull the leg straight to align the bones.
2. Immobilize the limb using a splint or padding in the position you found it; do not force the bone back.
3. Encourage the victim to stand and walk on the leg to check if it is truly broken.
4. Apply a tight tourniquet above the fracture.