I'm not saying it is or isn't. Quite a few comments on that particular video claim to be from the area and stated the case about fireworks.

Hard to prove shaking ground via cell phone footage, really.

And, you're not right on the 'have to be seen' with fireworks. Canada Day fireworks here in my city ; can't see them when they do them, can certainly hear them like they're next door though.

Again, I'm not saying it is, or isn't. Just pointing out the comments in the video.