accident
alluvion
alluvium
apoplexy
bloodless revolution
blow
bouleversement
breakdown
breaking up
breakup
calamity
casualty
cataract
catastrophe
cave
cave-in
clean slate
clean sweep
climax
collapse
collision
computer revolution
contretemps
convulsion
counterrevolution
crack-up
crash
debacle
deluge
diastrophism
disaster
engulfment
fit
flood
flooding
grief
ill hap
inundation
misadventure
mischance
misfortune
mishap
nasty blow
overflow
overflowing
overrunning
overthrow
overturn
avalanche
carnage
chasm
clash
commotion
conflagration
devastation
disruption
earthquake
eruption
havoc
holocaust
imbroglio
meltdown
perturbations
thunderstorm
turmoil
undertaking
upheaval