When photographs of spontaneous events miraculously appear on the Web, it generally prompts two responses: wonder and skepticism.

So it was with an image of exploding manhole covers in Omaha that took over the Web last month. On Sunday, Jan. 27, an underground fire cut power in half of downtown. A vivid photograph of unknown provenance, showing fire shooting out of manholes on a city street, began popping up on Reddit, where it had 1.5 million views, and Gawker.

The photo — an indifferently composed shot of an event that looks very far away — would not win any Pulitzers, but something incredible seems to be under way at the precise moment it was taken. You can almost hear the sequential explosions emanating below the street: boom, boom, boom as flames appear to shoot up from hell itself.

In this age of Photoshop, it wasn’t long before the debates cropped up, on the Web and in Omaha, about the picture’s authenticity.