I think there are no situations in which it hasn't worked. What we have are situations of some investigations being more challenging than others. Regardless of the challenges that are out there, we work our way through them and do our work. We come to the bottom line of what happened and why.
You asked me for one case that I thought was exemplary--I don't think you used the word, but that was the idea. I think the golden standard was Swissair 111. The investigation of the Swissair 111 crash was very complex, but the investigators were dogged, and the work they did was absolutely leading edge.