Bomb Threat? What?

Today there was a bomb threat at Landon's school. I almost had a full blown panic attack as I rushed over to get him (I left my class - luckily a teacher was there to cover - to run out and get him). I was not alerted (by email) until 2:15 (after all of the high school kids had already gotten home safely). His classroom is on the first floor of the highschool and there is an elementary school ATTACHED to the high school. Landon's class was moved to the library in the attached elementary school and just hung out there all-day-long. I was grateful to have been able to pick Landon up when I got there. I argued that I had 4 minutes in my favor with the nice man blocking my way. They were telling me that I couldn't get him between 2:30 and 3 because the elementary kids were dismissing early. So let me get this straight, dismiss all of the highschool kids at 12:15 (the threat occured at 11:30), move the four year olds over to a school that is attached to hang out in the library all day, dimiss the elementary kids next, and save the four year olds for last... huh? I don't get it... and still don't.