I struck a pedestrian and his lawyer is suing me.

I assume you struck the pedestrian with your car.  If so, notify your automobile insurer IMMEDIATELY about the summons and complaint, and explain the circumstances of how and when you received it.  They should provide you with a lawyer, who will call the other lawyer and arrange a schedule for answering the complaint.  I wouldn't wait too long, however.  If the insurance company doesn't provide a lawyer right away, call the plaintiff's lawyer yourself and explain that you just received the summons because the address was wrong, that you have contacted your insurance company and will be represented by a lawyer, but want to make sure that no default is entered.  Get his agreement to extend your time to answer for a couple of weeks.  Get it in writing (an email is fine)  DO NOT NEGOTIATE ANY SETTLEMENT; explain that you have to leave that to your insurer. If the insurance company won't provide a lawyer, and if the plaintiff's lawyer won't agree to extend your time to answer, or if a default has already been entered and the lawyer won't agree to have it vacated, you will have to make a motion to extend your time to answer or to vacate your default.  Given the circumstances you've described, your motion will likely be granted, but the sooner you make it the better.  If the insurance company will not provide you with a lawyer, you are probably well advised to hire one for yourself.