There are 25,000 light poles in San Francisco — or, rather, there were until today. Now there's one fewer: Redditors are reporting that a stories-high light post came crashing down at Kearny and Bush, closing that intersection.

What happened? While it's unclear, one theory that was floated during a similar incident last summer, in which a Nob Hill light pole came crashing down on a car, bears repeating. Urine, it was hypothesized, had eroded its base.

“We believe there was some contribution of dog or human urine on the base of the pole,” PUC spokesperson Tyrone Jue said at the time. That was reportedly the fourth pole to fall in the last two years. “We encourage people and dogs alike to do their business in other places, like a proper restroom or one of our fire hydrants, which are stronger and made out of cast iron," Jue said.

Related: Three-Story-Tall Lamp Post Collapses Onto Occupied Car, Urine To Blame