"caerse repentinamente" in English

to blow down- to come away- to come down- to come off- to come out- to drop- to drop off- to fall- to fall- to fall in- to fall off- to fall off- to fall out- to fall over- to go down- to pitch- to tip over- to topple- to tumble- to boob- to goof- to fall down

sharply- abruptly- suddenly