About 9 p.m. a couple of days ago I was sitting in my living room reading a book when I happened to look out the window and across the street. No sooner then I had looked up a purple and orange flame spurted up out of the sidewalk. It burned for maybe five seconds and then shrunk and disappeared. A friend of mine was there with me and saw it too. He later suggested that it may have been St. Elmo's fire although I am hesitant to believe this because of both the way it looked and the location it occurred (directly beneath a big eucalyptus tree). The next day I went out to the spot where I saw it and couldn't find any scorch marks or other evidence that a flame had burned in that spot. In fact the cement was evenly covered with leaves and there wasn't the slightest bit of evidence that anything had even been there.

There aren't any gas lines nearby and the electrical wires are all above ground, so I can't think of what this could have possibly been.

Also, there weren't any people out when this happened, so the chance of it being a prank or something like that is pretty unlikely.

Do any of you have any idea?

Thanks in anticipation,
Russ

This spontaneous fire, while intriuging may have a completely natural cause which you mentioned in your post..... none other than the Eucalyptus tree. The Eucalyptus tree has highly flammable oils contained within its leaves. During warm days these oils can vaporize and mix with the surrounding air creating a highly flammable concoction. In fact, in areas where Eucalyptus trees are prevalent, the vaporized oils cause a blue haze. It is possible that the oils on or near the sidewalk (as it was evening and with temperatures dropping the vapors would settle near the ground)were ignited (possibly by a cigarette ash) creating the flame that you saw. It does not surprise me that you found an even layer of leaves and such that were unburned, as the Eucalyptus tree is notorious for dropping its leaves and branches. The ones that you found the next morning could have very well fallen over night.

Well said, Obsidian!

Yes, thank you. That's a very probably explanation for it :-)

~Russ