A drunk 18-year-old man was arrested late Tuesday after running a stop sign, causing a two-vehicle crash and then fleeing in a hail of bullets fired from a third vehicle, Milwaukee police said. Three people were seriously injured in the crash, which happened at about 10:30 p.m. at N. 5th and W. Clarke streets. Police said the 18-year-old, from Milwaukee, was driving a 1998 Lincoln Town Car westbound on W. Clarke St. when failed to stop at a stop sign and hit a 2002 Toyota Avalon heading north on N.