I do not recall ever seeing anything quite like this.....

in a helicopter and very rarely on a plane - that is where basically a complete breakup instantly occurs. It was exactly like a plane suddenly losing both wings.

Just speculation: I can't see how it could be anything but an internal malfunction. I suppose a bird strike is possible but that would surprise me.

It is beyond horrific to think of what that poor family went through in those final seconds. - JamesJM