Death wobble is a real thing! From my understanding, basically enough vibration at the right frequency and off it goes. It seems you have to be doing at least 50 kmh and it can occur naturally or be induced by something as simple as tap on the handlebars (I've had it happen both ways). Clamping the legs on the top bar has worked for me; changes the frequency of the vibration for the frame. By and large, a terrifying event when it happens....
A good article on the subject
https://cyclingtips.com/2020/07/bicy...-to-stop-them/