david hartley had always been interesting in visiting the sunken church on falcon lake. on thursday morning, 2010, a week before he and his wife would move home to colorado, david decided they would go. >> did you know then what you must know now? that there had been several attacks on that lake that fishermen don't cross into mexico on that lake anymore? >> we did know that there were attacks. we didn't know where they were exactly. >> you had no worries whatsoever when you took the jet ski? >> no idea. >> and as tragic as this is, what i think i am hearing from you is what the hartleys did was incredibly stupid? >> incredibly. fishing guide and resort owner