UPPER DARBY, Pa.—A woman was raped by a stranger on a commuter train in suburban Philadelphia in the presence of other riders who a police official said, “should have done something.” Superintendent Timothy Bernhardt of the Upper Darby Police Department said officers were called to the 69th Street terminal around 10 p.m. Wednesday after the assault on the westbound train on the Market-Frankford Line. An employee of the Southeastern Pennsylvania Transportation Authority who was in the vicinity as the train went past called police to report that “something wasn’t right” with a woman aboard the train, Bernhardt said. SEPTA police waiting at the next stop found the woman and arrested a man. The woman was taken to a hospital. Bernhardt called the victim an “unbelievably strong woman” who provided police with a lot of information. She did not know her attacker, he said. “She’s on the mend,” Bernhardt said. “Hopefully …