I don't have all the information on your case, obviously, but I may be able to provide some information on how the bankruptcy system affects a personal injury
When the store filed bankruptcy a "stay" was automatically issued by the judge of the bankruptcy court. This means that all and any suits or attempts to collect from the store had to cease immediately. All cases in which they were involved in any manner were "stayed" as well. Your lawyer should have and probably did sue everybody in one suit so as long as the stay is in place he can't do anything against anyone in the suit without being in violatiuon of a federal judge's order. Techincally, he isn't even allowed to send letters back and forth with the other lawyers that affect the suit in any way.
He can seek a "lift of stay" from the bankruptcy court, but that doesn't mean the judge will agree to lift it and many times these aren't sought because they are fruitless.
The "empty seat" you mentioned is a reality in court. If there is a defendant who is not there they other defendants point at them and say it is their fault, making your case even harder to win. This is if you even could get permission to continue with your case from the bankruptcy judge.
You are not allowed to do anything without further action from the bankruptcy court.
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