Another portable toilet went up in flames at approximately 6:45pm yesterday evening on the 700 block of Chestnut street in San Francisco's North Beach.



This marks the 22nd incident since the arsons began in November. Generally, the blazes have been started in the early morning hours.



It's still not clear what, if any motive, is behind the fires.

Plastic portable toilets can melt in minutes after catching fire. They turn into a pile of molten plastic.

"These people, I don't think they're criminals, but they are kind of out of their minds to do that," Far West Sanitation & Storage containers president Alex Rodriguez told the Associated Press earlier this month.



San Francisco resident Rob Spectre has set up a map to track the blazes, clearly showing the cluster of incidents in the Marina, Russian Hill and North Beach neighborhoods.



Which makes it clear that at least there's some method to the arsonist's madness. Photo by Beau B.



Jackson West wishes there were more public toilets in San Francisco for all sorts of reasons.