Brad_Hawthorne
XrayMan
....So, who do they file the insurance claim against? The original wreck or the final one? 
Assuming the driver isn't at fault, then usually both. Plaintiff just has to prove both parties were negligent; the defendants fight it out for who's less at fault. If the driver was at fault for the accident, then the tow truck driver is going to be at fault for at least part of the damage.