I had a similiar thing happen to me a few months ago. I was at the monthly flea market here in Nashville and was talking to a dealer about something he had. After about 30 seconds I thought a bee stung me on my left knee. I swatted at it at then looked only to find out my pants were on fire! The booth next to his had one of those womens makeup mirrors sitting on the ground and the concave mirror caught the sun and was shining on my knee setting the pants on fire. Left a 2" hole in my brand new jeans. GEEEEEZ!!