After the Newtown, Conn., tragedy at Sandy Hook Elementary School last December, where 20 students and six educators were killed, new safety efforts swept through school districts. President Obama called on administrators and law enforcement officials to reevaluate emergency procedures.
School boards across the nation reacted with increased spending on security and stronger efforts at elementary schools, in particular.
The approach changed from one of keeping students inside to keeping outsiders from entering.
"The idea of fencing was to keep kids from getting out, not to keep someone else from getting in," said Kirk Lewis, assistant superintendent of operations at Riverside Unified School District, where higher fences, among other measures, are being put into place.