Destruction of Island
Scenario: Small Island nation is completely decimated by an unprecedented climate event. A combination of factors (e.g.: Cat 6 cyclone, sudden change in direction, storm surge, king tide, SLR, unstable coastline, landslides etc.) when combined lead to the event much more deadly than anticipated - citizens are taken off guard, are not pre-warned or prepared and thus fatalities are high.
SLR
IPCC on SLR indicates that low lying nations like Tuvalu (average elevation 2m) will unlikely be inundated this century. The possible collapse of the Thwaites glacier in Antarctica could bring this forward. Storm surge is the more immediate risk, especially when it occurs multiple times a year.