> * Mary Carmack-Altwies said there were 'so many levels of failures' on set of 'Rust' that led to the fatal shooting of cinematographer Halyna Hutchins * The District Attorney has said she knows who loaded the gun * She added that there were additional live rounds found on set and refuted claims that the shooting was caused by sabotage * Hutchins was shot when a gun held by actor Alec Baldwin went off during filming