Your reply is like a contraction, tho. It may be common to spoken language, but not the written word, which is really what we are all learning here. It woulda coulda shoulda still been "In case OF what?"
In case of emergency! But I see your point. :)
I put "If what?" and Duo accepted. I wasn't entirely comfortable with that answer either, but I chose it as the lesser of two odd sounding translations.