Correction
Correction on incineration at the epicenter. My reply was written without rereading the text and was more appropriate for an earlier item. The altitude of the airburst and the blowout effect of the shockwave could account for survival of trees at the epicenter with regard to incineration. This issue has not been considered a major mystery by those investigating the event. I was responding to what was initially considered the mystery of trees left standing in the center of the blast.