Had that happen to me many years ago- but it was an OMAS hub, laced radially, with 36-spokes. (By now the experienced wheelbuilders are probably cringing.) I was truing and tensioning it when about 1/4 of one flange let go with BANG. I think aluminum shrapnel went flying through my hair.

Just a case of not enough flange and too much tension.

I eventually sawed the hub in half and used the intact portion as a shift knob on my old VW. Waste not, want not.