Dan Hausle tweets officials began a "controlled dismissal" of students around 11:45 a.m.
Brianne Dupuis adds:
Watertown High on lockdown since 8:15, no notice to parents, only found out from my cousin who is there!
So we are getting evacuated in the lib but theyre checking everyones backpacks before we can leave
â€” â€ NanÃ©h â€ (@Nanehp3) December 20, 2013