"went down" is a slang phrase to simply mean "happened in a serious, sometimes violent, manner" "go down" is a dangerous phrase to use (which you used in the title). It can sometimes mean the present or future tense of "went down" above ("Something's about to go down!") but, in certain contexts, it can mean something rude/sexual. If you see the construction "Going down on (insert person's name/pronoun here)" , it is a rude phrase. I like to point these out because they are something that I think it is important to know about even though it's something people don't like to talk about. Hope this helps :)