"dry ice bombs" in LAX
"dry ice bombs" in LAX and dry ice in bottles "exploding" in "restricted access" areas...
Dry runs to gauge response. Just like when a group of swarthy allahuing males act up on an airplane. (And, not entirely unrelatedly, like the EBT test this weekend.)
Plus, a mere scare is still a minor hit when instilling terror is your goal.
Be calm and carry on.