Sirens (Plus Tangents)

Does anyone know why the sirens are being checked on Wednesdays instead of Saturdays? More pertinently, why did Westside have a tornado drill during a lunch mod? I think they should have drilled during 1-3 or 12-14 to allow students to have time to eat. Tangentially, if there ever were an intruder alert, all the intruder would have to do is look in the glass windows on all of the classroom doors and see the backpacks/notebooks/laptops left on the desks to know that students were in the room. Simply moving the people into a corner would probably not be effective in that scenario. Even more tangentially, perhaps the reason that the siren is so annoying is to convince the intruder to leave the premises and forget their dastardly plans entirely.