You SIGH as 2 disasters strike your birthday party - KKK plus a fire.
a personal misfortune: house burned down, father had a stroke
natural disaster - earthquake, fire, flood, your mother's flattus, etc.
a slightly more newspaper-ish word for a harmful blaze.
this means disaster - not in the sense of earthquakes or tsunami. Disaster in the sense of 'How was your trip to Tahiti?' 'Oh my god, it was a total disaster!!! First we missed the plane, then I got an infection, then on top of all that our hotel was run by zombies!'
災難 carries the sense of a bunch of random unconnected misfortunes. It never rains, but it pours, kind of thing.