Tearing everything to the studs and sub floors to find tons of rotten sub-floor and roof trusses.

There had been a fire at some point as there was fire damage to some of the original floor trusses, and the giant third floor attic was converted into a large master suite (which made it a great property to live in as we had 2 floors of living space). 

A couple things that stood out to me:- Current county tax value shows $362k.

A couple of years ago I came across this property when I was looking at the multiple listings, and it immediately stood out to me as an opportunity.The property, a six unit apartment building about a mile from the USC campus in LA, was being marketed by a residential real estate agent at $1.250 million.

I then watched the recording of the No/Low Money Down Webinar, and as someone who has little capital and significant student loan debt, the idea that stood out to me was Brandon's example of using a master lease option on an apartment complex for 6 months to raise capital for the down payment on the same complex which was financed by the owner/seller.

It's impossible for us to know the extent of the damage to the structural members (rafters, trusses, and then floor joists etc) and that will impact how extensive of repairs are required.If you've never done anything quite like this, I'd be concerned.It doesn't sound like this is a good first project.

The only thing that I was able to see is they appear to be in fair condition on the outside, I stood in a place where I can see that all of the roofs look fine, and I went inside one unit that needed no repairs. 3 units share 1 septic, 2 are on their own septic. 

BRRRR stood out to me right away because it seemed like a way to pay back a lender within a reasonable time frame without having to liquidate the deal at the end as in a flip.

The upside is that they are usually well built and have obviously stood the test of time.

Something that stood out from your post above is that you are active military.