[GregoryFul]

How about La Palma, the volcanic island in the Canaries. It has a fissure separating a huge chunk of the island apparently ready to collapse into the Atlantic, potentially causing a mega-tsunami that will eventually inundate the eastern seacoast of the US. The wave would be hundreds of meters high, and travel as much as 30 miles inland. The event could be only one eruption away. The east coast of the US would have at most, 8 hours advance notice.

I wonder if a few well placed explosives in the fissure could cause a premature collapse?

[Strategerist]

It has a fissure separating a huge chunk of the island apparently ready to collapse into the Atlantic, potentially causing a mega-tsunami that will eventually inundate the eastern seacoast of the US

The opinion of the overwhelming majority of tsunami scientists is that the collapse would not generate a long-range tsunami and the mountain isn't any particular threat to the US.