Sleeper, thanks for finding the Delta safety audit done a decade ago on Korean. I haven't read it for many years, but it is still an exhaustive but fascinating document. I believe that it was probably this audit that in part led to the AF board to seek DL's help on their possible safety issues. DL's last passenger fatalities occurred in a 1996 MD88 uncontained engine explosion on the takeoff roll in Pensacola. Two passengers seated adjacent to the engine lost their lives.
Here is a 2001 article briefly dealing with the DL safety program:
Safety Strategy Focuses on Little Things to Prevent Big Catastrophe | Air Safety Week | Find Articles at BNET