TAKKK/ CC BY-SA 3.0 Fertilizer and animal waste are causing increased air pollution.
Courtesy of CATHERINE PALMER 860.000 Catholic pilgrims flock to the Benjamin Franklin Parkway in Philadelphia to hear Pope Francis.
Courtesy of CATHERINE PALMER The two-hour Papal Mass was held in front of the Philadelphia Museum of Art on the Benjamin Franklin Parkway and attended by about 860,000.
Courtesy of CATHERINE PALMER Pope Francis visited Washington, D.C., New York and Philadelphia.
Courtesy of ROLLIN HU Vendors at Project Homeless Connect served about 2,000 homeless.
LEON SANTHAKUMAR/PHOTOGRAPHY EDITOR Panelists discussed the aftermath of the Baltimore uprising Wednesday.
