More than a dozen school districts have canceled classes across a wide swath of southeastern Kentucky as a grueling search stretched into a third day for a gunman who opened fire on an interstate highway and wounded five people over the weekend. Administrators in Rockcastle County, just north of where the shooting took place, said in a social media message that they decided to close classes while the shooter is still at large ”out of an abundance of caution” to ensure the safety of students and staff. Classes were also canceled at three regional college campuses. Authorities are vowing to keep up a relentless search as the stress level remains high for residents and police.