I wasn't in China but this is a true story...A Chinese village was left with a giant mass of soap suds when a person cleaning plastic bottles let too much soap go down a drain.

This is from the Nanning City area of the Guangxi Zhuang Autonomous Region

Locals reported that a villager was cleaning some plastic bottles and allowed a large amount of soap to go down the drain. The soap started to bubble when rain fell into the drainage area and stirred up the soapy water.

I guess the city is now a lot cleaner :-)