I love the idea that they're running a covert cover up by blocking up an entire motorway and blaring warning sirens. Yup warning people with sirens and alerting half the city to something is the best way to cover something up.
Police sirens are used to alert the publics attention to an emergency. Its the same stuff with people thinking UFOs are flying around with signal lights on and trying to hide.
And you think 50-100 cop cars traveling somewhere with no lights on secretively is not more suspicious lol?
Obviously they deemed whatever it was an emergency and needed to get everyone off the road so they could get there as soon as possible - which requires the use of sirens and lights.
In Australia we had a case where 3 UFOs appeared hovering in the sky above the adjacent oval to the schoolgrounds.
Many kids raced out of their class (along with their teachers) to get a closer look at what was happening.
One landed, left weird marks in the grass (which were physically documented), rose back up after a time, rotated onto it's side and took off, disappearing into thin air - although that's not the point.
The military swarmed the school a short time later - telling the children that they didn't see anything, and threatened the teachers that they would lose their jobs if they spoke about it, as they would have been "drunk on the job" to have seen a UFO.
The point is: sending the military down to a primary school makes things that much more suspicious, but when this "event" is impacting a large amount of people, with no real idea of how it ends, it's not that crazy to expect that they'd send almost everyone on hand at the time.
Also, when you have a history of successfully shutting any incident down, by trivialising it ("couple of crazies think they saw little green men and are forgetting that there were multiple weather balloons in the sky today", why would you even be concerned about the attention your response might bring.
Everything that's ever happened has been largely dismissed by the fast-asleep public.
Again, not saying this Miami Mall thing is a case of some kind of phenomena, but certainly a story of intrigue, which whether true or not, is being instantly dismissed by most people in the same manner as everything else ever has been.