The SS United States ocean liner, seen here docked in Philadelphia in 2013, was built in 1952 for United States Lines in an attempt to capture the trans-Atlantic speed record. Landov hide caption

itoggle caption Landov

Pilar Cedeno, of Hackensack, N.J., prays as Mass is celebrated by Pope Francis is broadcast to crowds on the Benjamin Franklin Parkway from inside the Cathedral Basilica of Saints Peter and Paul, on Saturday in Philadelphia. David Goldman/AP hide caption

itoggle caption David Goldman/AP

Tanya Brown-Dickerson (right), the mother of Brandon Tate-Brown, who was shot by Philadelphia police last December, listens to attorney Brian Mildenberg during a news conference on June 15 outside Philadelphia's City Hall. Brown-Dickerson is suing the city over the fatal shooting of her son. The police department did not initially name the officer who shot him, sparking protests. Matt Rourke/AP hide caption

itoggle caption Matt Rourke/AP

Pep is featured in the Dec. 26, 1925 issue of the Boston Daily Globe. But Gov. Pinchot's wife, Cornelia, later set the tall tale straight in an interview with The New York Times. The Boston Evening Globe / Courtesy of Boston Public Library hide caption

itoggle caption The Boston Evening Globe / Courtesy of Boston Public Library

St. Laurentius, a polish Catholic church in Philadelphia's Fishtown neighborhood, was closed in March amid fears that it would collapse. Since then, the community has pushed back to save the historic building. Kim Paynter/WHYY hide caption

itoggle caption Kim Paynter/WHYY

A Philadelphia mural entitled You Go Girl by Jetsonorama and Ursula Rucker. This is just one of many murals that the city's Mural Arts Program helped to create. Steve Weinik/Courtesy of the City of Philadelphia Mural Arts Program hide caption

itoggle caption Steve Weinik/Courtesy of the City of Philadelphia Mural Arts Program

Officials attend the launch of a Positive Train Control system for Los Angeles' Metrolink commuter trains in February 2014 at Los Angeles Union Station. Congress mandated the technology after a Metrolink engineer ran a red light while he was texting and crashed head-on with a freight train in 2008. Damian Dovarganes/AP hide caption

itoggle caption Damian Dovarganes/AP

Inside a Brown's Super Store. Brown's operates seven profitable supermarkets in low-income neighborhoods in Philadelphia. Courtesy of Brown's Super Stores, Inc. hide caption

itoggle caption Courtesy of Brown's Super Stores, Inc.

Emergency personnel search through the wreckage of an Amtrak train that derailed Tuesday night in Philadelphia, killing at least five people who were on board. Joseph Kaczmarek/AP hide caption

itoggle caption Joseph Kaczmarek/AP