Coming just four days before the anniversary of the Columbine school shootings, the mass slayings by a student gunman at Virginia Polytechnic Institute last week revived vexing questions and raised familiar fears for educators across the country who grapple daily with ensuring the safety of their students and staffs. The April 16 killings provoked the same questions that arose for K-12 officials after the 1999 rampage at Columbine High School and a string of other such incidents in the past decade: Could this happen at my school? Are we prepared? What are the warning signs that students may harm themselves or others? The Virginia Tech mass slayings also prompted school officials from suburban Washington to the West Coast to pledge heightened security measures and assure anxious parents and students that their schools were safe. "There are warning signs that everyone from teachers and counselors to administrators and fellow students need to recognize and report to someone responsible," said Cathy Paine, a psychologist in the 11,000-student district in Springfield, Oregon. Peers, said Paine, can be the best source of information, and school leaders must not only encourage students to report signs of trouble, but also make it easy for them. Offering students the option of reporting anonymously, she said, is important. Other signs to be on the lookout for, some educators said, are those that are described in a threat-assessment guide that the U.S. Secret Service put together after the killings at Columbine High.