The Tsunami was for real and is well documented in the Bahamas
There is a program on Discovery Channel describing wave action created by land slides. There was a mountainslide on one of the Canary islands that produced the wave that made great landscape changes on tese islands just off the Florida coast. It is reasonable that some indication also exists in Florida. My recall says the Bahama event wwas not as old as that described in this thread.
The ominous thing is that the volcano producing the slide will slide again. The volcqanologist in UK and the wave scientests in Switzerland predict large damage and huge loss of life in the Bahamas and Florida.
I've worked as a soil scientist on the Coastal Plain now for 17 years, and I have seen abundant evidence in Cretacious-age sediments of at least one, and perhaps several, very large tsunamis hitting the area that is now South Carolina. (In those days North America was in an equatorial latitude). I've also seen some indirect evidence which leads me to suspect a few of them happened at intervals in the late Tertiary/early Quaternary periods. I think catastrophic Tsunamis happen more often than we realize (although still infrequently enough that it's unlikely that we will witness one.)