What to do if there was a car wreck by my house and as I was looking for survivors I tore my Achilles tendon?

I am not sure who you think you might be able to sue for your injury?  The driver who caused the accident is not responsible for the fact that you chose to approach the accident scene and look for "survivors" and somehow in doing so, you tore your Achilles tendon.  When you chose to engage in an activity like this, or make the decision to approach an accident scene, you are assuming the risk that you may be injured.  As such, this becomes your liability.