Lol, is it that island (Las Palmas?) in the Canaries?
It's quite feasible apparently, because half of the island has already slipped during the last earthquake in the 40s/50s or whenever. One day they think the whole side could slip into the sea - but they don't know when (or if).
Apparently something similar happened 1000s of years ago, which could explain the occurrence of huge boulders stuck on top of cliffs in central America, which couldn't otherwise have got there.
I like the doom-laden narrators they choose for these kind of programs.
There was a spate of them during the pre-millenium doomsday period in the late 90s.