Carolyn Beeler updates us on the situation in Paulsboro, Gloucester County, where a train car carrying hazardous vinyl chloride derailed last week, spilling the chemical and sending dozens to the hospital. We talk with Ambassador Thomas Graham Jr., one of the world’s leading experts on nuclear non-proliferation, who’s speaking in Philadelphia tomorrow. Peter Crimmins reports from this weekend’s children’s concert performed by the Philadelphia Orchestra. Franklin Institute Chief Astronomer Derrick Pitts takes a weekly look at the night sky. And Chris Satullo considers what it means to be a leader.