Two men were shot, one fatally, when gunfire erupted in Tompkins Square Park on Friday morning during what law enforcement sources said was a drug-related burst of violence. The two victims, 74 and 44, were blasted in the back around 9:50 a.m. at East 7th Street and Avenue A, within the historic East Village Park, cops said. Both were taken to Bellevue Hospital, where they were initially listed in stable condition, police said.