Happen
Occur
Synonyms Occur, come about, come into being, result, materialize, be, come up, pan out, follow, emerge, present itself, go down, betide, eventuate, take place, come off, ensue, transpire, arise, crop up, fall out, turn out, develop, surface, supervene, come to pass, chance, and hap.
Discover unexpectedly
Synonyms Discover unexpectedly, find by chance, stumble on, light on, come across, blunder on, uncover, bring to light, run into, bump into, run against, find unexpectedly, chance on, hit on, come on, run across, unearth, locate, meet by chance, encounter, and dig up.
Chance
Synonyms Chance, have the ill luck, have the good luck, have the good/bad/ill fortune, and have the bad luck.
Example Sentences
Accidents can happen very unexpectedly sometimes.
What will happen during the event?
Things always seem to happen quickly.
Miracles can happen every single day.