Twenty years ago a United Airlines plane crashed into a former coal field near after a struggle in the cockpit between the passengers and al-Qaida hijackers.

The Flight 93 National Memorial near Shanksville, Pa. is the final resting place of the 40 passengers and crew - sacred ground and a monument to the sacrifice they made.

Since 1998, a black-and-white photo has appeared every Monday in staff photographer Tom Gralish’s “Scene Through the Lens” photo column in The Inquirer’s local news section. Here are the most recent, in color:

» SEE MORE: Archived columns and Twenty years of a photo column