Pennsylvanians and others commemorated the September 11th terrorist attacks in Shanksville, Pa. yesterday.  On the 22nd anniversary, hijackers took control of four airplanes and crashed them into the World Trade Center towers in New York, the Pentagon in Washington D.C. and a field in Shanksville, Pennsylvania.  Thousands were killed including the 40 passengers and crew aboard United Flight 93 that went down in Somerset County.  A Service of Remembrance was held yesterday morning at the Flight 93 National Memorial in Shanksville.  Second Gentleman Douglas Emhoff, the husband of Vice President Kamala Harris, attended the event with Pennsylvania Governor Josh Shapiro and his wife Lori.