Then you shoot and kill the intruder. The same goes for car thieves. Make sure you say that you feared for your life and do not shoot them in the back, only prison guards can legally backshoot a person. Besides your personal emotions and feelings it's a straightforward occurrence and the law is on your side.
If you are being sarcastic or humorous, please use a smiley or write it out after your post (e.g.: "/sarcasm").
If you meant for your post to be serious, please refrain from carrying for the time being, and please reevaluate your reasons for carrying.
To the OP: if you are in fear for your life because of a legitimate threat posed by the intruder, chances are you will have to fire, and because you don't want to hit any innocent passerby on the street, you will likely aim center of mass to reduce the likelihood of missing ("shoot him in the leg" only works in Hollywood). Yes, this may bring about the death of the intruder or intruders, but your first priority is stopping the threat, not arresting criminals.
Don't expose yourself to any more legal or bodily harm than you have to by firing a "warning shot" (negligent discharge within city limits and could be argued in court as a sure sign you had time to react and weren't in a life-or-death situation), aiming for the leg or arm (chances are you will miss and will have to account for where that projectile end up), or using "less lethal" devices (stun guns and pepper spray that do not always work anyway, and are wholly inadequate in a life-or-death situation).