April 4, 2011 7:26 am School Superintendent Threatened There is tighter security at Philadelphia School District Headquarters after Superintendent Dr. Arlene Ackerman gets a threatening email over the weekend. US & World Videos 2:42 Search continues for missing kayaker along Schuylkill River 2:26 Beloved cheesesteak shop Jim's Steaks reopens 2:21 Man sprays liquid on tents of pro-Palestinian protesters at Penn, police say 2:05 Wednesday's Child: Gianna 10:45 ‘Giant Heart' procedure: The Lineup
