>>1529639 (lb)
Does seem like a lot at once. Almost like coordinated?
Even if they are deemed "pranks", FYI Santa Fe HS (5-18-18) had a similar "prank" shortly after the Parkland shooting.
>https://www.houstonpublicmedia.org/articles/news/2018/02/28/270523/no-threat-found-after-texas-school-put-on-lockdown-santa-fe-high-school/
There was also a similar "prank" at a Santa Fe HS in Atlanta around the same time period.
So thanx for keeping your eyes open. Might be worth a deeper look once everything is settled.
Right now, prayers that no one is harmed.