The phrase is Kölsch dialect for a standard German question asking what caused something, but the exact recording source and speaker are not documented. It circulates on soundboards under the TOAC and Woran tags, filed with prank clips because of its drawn out, baffled delivery. At close to twenty seven seconds it is longer than most reaction sounds, so creators tend to use it as a full voiceover rather than a quick sting. Its appeal is the everyday sound of someone genuinely puzzled by a failure.