Mist

Yesterday, I was walking in Downtown Tulsa when I came across this... thing.

Rarely have I come across a section of sidewalk that was vomiting mist up into the sky. Even better?... the little guardrails make it look like some kind of pathetic miniature circus attraction.

What could be causing this Random Mist Event? I have some theories:

1) An underground hot-water pipe developed a leak, releasing pressurized water vapor into the air.

2) A dragon lives under the street. Angered by our urban ways, he is preparing to burst forth from the depths and eat us all.

3) The sidewalk had spicy Mexican food for lunch. ¡Arriba!

Actually, that first one sounds a bit shifty to me. Prolly can discount that one.

What do you think?