In a horrific incident in Philadelphia Fairmount Park Mass Shooting on Memorial Day Leaves 2 Dead, 9 Injured. Philadelphia’s Fairmount Park became the scene of yet another tragic incident of gun violence in the United States, as a Memorial Day gathering ended in horror late Monday night. A mass shooting on Lemon Hill Drive around 10:30 p.m. left two people dead and nine others wounded, including three teenagers. The victims were caught in a barrage of gunfire while attending a large gathering at the popular park.