To kick off a week of first hours dedicated to exploring the anniversary of the Sept. 11, 2001 terrorist attacks, we take a look at three ways in which 9/11 reverberated in the Delaware Valley. We’ll talk to DARRYL BACCHI, a volunteer firefighter with King of Prussia Volunteer Fire Company, Bridgeport Fire Company #1, and an honorary member of Brooklyn’s Squad 252, which lost several members in the collapse of the Twin Towers. Bacchi spent nine months working on “The Pile,” the smoldering rubble that remained at the World Trade Center, and is working to build a memorial in his King of Prussia firehouse. Then we’ll talk to MOEIN KHAWAJA, executive director of Council on American-Islamic Relations’ Philadelphia Chapter, about how the attacks and their aftermath were experienced by Muslim Americans in the country and the Philadelphia area. Finally, we’ll talk to Philadelphia Inquirer architectural columnist INGA SAFFRON, who will discuss the myriad ways in which terrorist attacks in New York and Washington DC changed the physical landscape in Philadelphia, from concrete barriers disguised as planters in front of federal buildings to a controversial fence on Independence Mall that was not built.