When a major expense occurs, I can easily sell the security and have cash to pay for the expense. 

Work it out and secure the place.  

You can get 10% on a note secured by real estate with a low ITV.  

., generally-speaking, the populated areas of Riverside and San Bernardino Counties and maybe some of the cities in Los Angeles County that border San Bernardino County.

By the sounds of it the equity you have in your current properties is a significant tool you can use to secure financing of some kind including a home equity line of credit or maybe a refinance.

All the books and articles you have read will give you a false sense of security making you think that real estate investing is safe.  

~verbatim"At least one borrower must occupy the property and sign the security instrument and the mortgage note for the property to be considered owner-occupied.

I have a friend in commercial real estate securities who says that the large commercial securities is starting to look shakey and residential tends to follow not far behind.I agree that a correction is coming soon, but I do not think that we will have the bottom fall out like we did 8 years ago.

The tenants also probably have a security deposit that you will be on the hook for when they move out. 

There could be some security with the hoa in regards to not getting killed with a sewer line or some other outside expense..old tree falling, earthquake damage.