That was my initial guess. It could also have been a contained failure that damaged the cowl, which later separated from aerodynamic stress. But the missing f

That was my initial guess. It could also have been a contained failure that damaged the cowl, which later separated from aerodynamic stress. But the missing fan (and maybe a compressor stage) does seem to imply a shaft failure. The main question is whether that was the beginning of the event, or a later result from a different failure.