DT Alpine III spoke broken at top nipple thread
This spoke broke on a wheel subjected to extreme disk brake vibration. Usually when spokes break under these conditions they break at the elbow, but this one broke at a nipple thread. There could have been a flaw or small imperfection in the thread that allowed a crack to progress through the thickness of the spoke. Note that the dark surface has oxidized and been exposed for some time, while the light-colored metal is the thickness of spoke that broke suddenly at the time of failure.