COLUMBUS, Ohio – Police, school employees, security consultants and others say threats to schools are increasing nationwide.
They come both from local students and outsiders seeking to cause disruptions or a big emergency response.
One researcher estimates there were about eight bomb threats per school day nationwide during the 2015-16 school year, and that doesn't include other threats of violence or disruption.
Ohio is believed to be among the states with the most threats. The Associated Press tallied more than 170 there in the 2015-16 school year.
Learning time lost to evacuations and cancellations adds up, as do the hours police spend responding and investigating.
Less measurable are the ways threats can dent staff and students' sense of security even when they're false alarms, as they almost always are.