Niagara Falls is not on the Atlantic Fall Line, Ann. The Fall Line describes the edge of the continent whereas the Falls are in the interior. The origin of the Falls is linked to the advance and retreat of the last glaciation. The explanation is complex, and I think the Niagara Parks people from Canada did a great job here:
Niagara Falls Geology Facts and Figures
I did not see your Red Arrows, but I do believe we heard them! I wondered what that great commotion was, and asked OH if he knew, which he did not. Mystery solved! I see by one of the local papers that they were on their way to a show at the Canadian National Exhibition, which was a yearly must-do for us. My mother took me every year when I was young.
Red Arrows to fly over falls Wednesday morning
And once again, apologies for the hijacking and back to WDYTYA. I have to say the summary here of Sharon Osbourne's story has opened my mind a teeny bit. I don't think this show is available here yet, but I'll keep it on my radar.