Years ago, I consulted somebody in-the-know who shall go nameless on what kind of warning and how much time we in Fredericton would get if the Mactaquac dam, about 12 miles upriver from us, were to burst. He said the first warning signs would be a rumble from that direction, and a displacement of air and mist. Then anyone caught downtown would have about two or three minutes, five at most, to go into Feet-Don't-Fail-Me-Now mode and find the nearest high ground or sturdy building four storeys or higher - he said the parking garages would have the best chance of holding up to the water and debris. Then, pray. – Monique, artist chick.