Katie Colaneri reports on the Pennsylvania DEP’s warning to Chevron, which blocked the agency’s access to a fatal gas well site in February. Kevin McCorry visits Philadelphia’s Bartram High, where an experienced educator is straightening out the violence-prone school. Shirley Min looks at controversial proposed data center at the University of Delaware. Dave Heller previews the Philadelphia Film Society Spring Showcase with Andrew Greenblatt. Author and illustrator Allen Crawford discusses his new book on Walt Whitman’s “Song of Myself” with Dave Heller.