Chronicled incidents of spontaneous human combustion, where a person bursts into flame with no apparent cause, date back to the late 15th century.
Of the more recent episodes, however, none has been cited more often than that of Mary Reeser.
A 67-year-old resident of St. Petersburg, Florida, Resser spent the evening of July 1, 1951, in an unremarkable way, receiving visits from her son and a neighbor. At the time, Mary Resser was wearing a rayon nightgown, bedroom slippers and a robe. When they left her, everything in the apartment appeared normal.
The following morning a telegram courier arrived and received no answer to his knock at the door. Summoning the same neighbor, they found the doorknob hot to the touch. The neighbor asked nearby construction workers (some sources say policemen) for help getting into the apartment.
Once inside, they found the apartment unusually warm, even though some of the windows were open. In one corner of the room they found a pile of ashes, the burnt remains of a chair and lamp, and an electric clock with a melted plug that had stopped at 4:20 a.m. Other than the charred remnants in this corner, the apartment was completely undisturbed. Upon closer examination, they found a woman’s left foot, still wearing a slipper, in the ashes (some sources say a shrunken human skull was also found). That’s all that was left of Mary Reeser.
There was no sign of a break-in or a burglary or any other outside influence in the apartment. The authorities were stumped and began to call in consultants to help.
To the experts, clearly this was no ordinary fire. They estimated that a fire of 3,000 degrees burning for several hours would be needed to consume a human being so thoroughly. With a fire that hot, burning for that long, why wasn’t the rest of the apartment, if not the entire building, burned down?
St. Petersburg police solicited the help of the F.B.I., but the Bureau couldn’t shed any light on the situation.
Physical anthropologist Wilton Krogman, a consultant on the case, wrote: “”I find it hard to believe that a human body, once ignited, will literally consume itself — burn itself out, as does a candle wick…never have I seen a body so completely consumed by heat. This is contrary to normal experience, and I regard it as the most amazing thing I have ever seen…as I review it, the short hairs on my neck bristle with vague fear. Were I living in the Middle Ages, I’d mutter something about black magic.”
Possible explanations have been put forward ranging from ball lightning to explosives. After an investigation that went nowhere, police finally, and lamely, put the cause as “a neglected cigarette.”