This is general discussion and not intended as legal advice, nor does it form an attorney-client relationship. A thorough review of your particular facts must be completed prior to advising on this situation.
Well, it depends. California has some very good laws that protect borrowers after foreclosure. Often the best protection is the foreclosure process.
Your case depends on whether or not the second loan was obtained when you purchased your home, or was it obtained after you purchased. CA has non-recourse loans if they are "purchase money" loans where the lender can only seek the property and not a "deficiency judgment" for outstanding balances. This protection extends to second loans if they were obtained when the property was purchased. So you may not have to pay anything.
Often, lenders try to recover money and at times even sue on loans that are completely protected, but if the borrower does not respond to the lawsuit, lenders can obtain a "default judgment" and lien the borrower.
If the second loan was not a purchase money loan then you may be subject to a deficiency judgment after the lender files a lawsuit for the unpaid amount. When this happens, I see people come in to file bankruptcy in order to avoid the cost of litigation and the dollar amount in the loan.
I have some info on sdhomelaw.org you can look over. Good luck!