Jackson Hole Fire Marshal Kathy Clay has issued a ruling on the cause of the blaze Sunday night which destroyed a multi-million dollar home near Jackson. Clay says while the extent of damage to the point of origin was such that a complete investigation was not possible, it is certain the cause was chimney-related. Clay says the most probable cause was either pyrolosis – which actually changes the chemical make-up of organic material to something that ignites at much lower temperatures – to the wood structure behind the masonry fireplace and chimney; or she says it may have been the effects of “extension” into those concealed areas if the masonry had gotten cracked over the years. Clay points out that those having older fireplaces surrounded by frame construction might be well-served to have the concealed spaces behind them inspected to assure they are not suffering such a condition. Says Clay: “It’s cheaper to replace a malfunctioning fireplace than it is to rebuild a house and replace all its contents.” The house was owned by Hillwood Bar-BC Land Company who’s founder and Chairman of the Board at the time the home was purchased was Ross Perot, Jr. The property had been listed by Sotheby’s International Realty for $21-million.