The National Park Service is reporting a visitor on one of Mammoth Cave's tours died this afternoon. In a press release, spokeswoman Vickie Carson wrote: William Larry Martin, 67, of Bronson, Florida, was on the 11:00 a.m. Historic cave tour when he became ill in River Hall, about one and one-half miles into the two-mile tour. The tour guides telephoned their supervisor on the surface for assistance at 12:20 p.m. and immediately began CPR. Emergency medical technician rangers and a rescue crew entered the cave at 12:35 p.m. and arrived on the scene at 12:45 p.m. In River Hall, rangers administered CPR and applied an AED. In spite of these efforts, Mr. Martin did not survive and was declared dead at 1:18 p.m.Martin's cause of death isn't know. Carson says to the best of her knowledge, the last time a visitor died in Mammoth Cave was in the early 1980s.