HARRISBURG – PA State Police have opened a DUI investigation following the deaths of two troopers and a civilian struck by a vehicle on Interstate 95 in Philadelphia early Monday. Police said Trooper Martin Mack III and Trooper Branden Sisca were trying to get a pedestrian off the interstate when all three were struck by a vehicle traveling at a high rate of speed. The troopers and the civilian were pronounced dead at the scene. Police said the driver remained at the scene and a DUI-related investigation was opened. State Police Commissioner Col. Robert Evanchick spoke at a press conference with Gov. Tom Wolf, who said this tragedy is a reminder that our law enforcement officers put their lives on the line every day, and we Pennsylvanians are grateful for the men and women who protect us and our communities. Wolf ordered state flags to fly at half-staff in the troopers’ honor.