Sinkholes

After 10 months of waiting... we're about to pour concrete when my contractor calls and says, "We have some sinkholes in your backyard."

Sink holes... WTF?!?!

I hurried from TKA all the way back to the San Jose home to deal with the 8" mysterious hole in my foundation.  What's causing the drainage and erosion? Do I live on an unstable foundation??

What do I do??? Not a moment to spare. 

Either you don't do jack... but once you open the patient... all the problems fly out of Pandora's Box.