A Sellersville man has admitted causing a fatal head-on collision while high on drugs. 24-year-old Stephen Strassburg, of North Main Street in Sellersville, pleaded guilty to homicide by vehicle, driving under the influence of drugs and related offenses. Laboratory tests found that he had marijuana and a prescription anti-anxiety drug in his system at the time of the early-morning crash on July 30 of last year, on County Line Road near Richardson Road in Montgomery Township, and his license was suspended as a result of a previous DUI conviction. He was also speeding when he crossed over the center line, crashing his Buick Rendezvous into a Suzuki Vitara driven by 50-year-old Wayne Cooper of Philadelphia, who was pronounced dead at the scene. He and a co-worker, 46-year-old Tyrone Moore of Philadelphia, were headed to a nearby Wawa store during a break from their jobs at Vertis Communications, a New Britain Township printing shop.