Zachary Hartwell's parents are suing Dunn's estate and the restaurant where Dunn was drinking before he crashed his Porsche 911 GT3 around 3 a.m. on June 20, 2011.
Police say Dunn had a blood-alcohol level more than twice the legal limit for drivers and was going as fast as 140 mph before the one-car crash.
The suit first reported by Courthouse News Service says Dunn was visibly intoxicated and shouldn't have been served by the restaurant. A state police investigation, however, cleared the bar of wrongdoing.
A phone message left for a lawyer for Dunn's estate wasn't immediately returned Thursday