It's too soon to even begin to figure out why, but it's time for schools to figure out how to seal themselves from threats like the one that led to the massacre in Newtown Connecticut.
Today many schools across Metro Detroit are feeling anxious as students return to classes after the Sandy Hook Elementary School shooting.
Schools are calling on police officers. Staff sits inside listening to emergency scanners – most with the doors locked.
Watch the video for FOX 2's Roop Raj's full report.