They're sued and go bankrupt.   

Does anyone know a website where I could find commercial listings or even bankrupt apartment listings covering all states?

If you prohibit private investors from investing in hedge funds which on average use 1.5-2 times leverage but permit the same investors to invest in banks which use 25 times leverage and which are for all intents and purposes bankrupt, then you either don't understand the world of finance or you don't want to understand.

I took loan for a private owned property and the fear of losing came into my mind as my neighbor become bankrupt.

I'm not stretching myself and can afford a loan, but my concern is that a correction would cause me to go bankrupt.

If the answer is negative, you are technically bankrupt."

These "quant" techniques seem to work 99% of the time and they also tend to bankrupt the firms the remaining 1% of the time.

I had this happen to me twice where I was reported bankrupt, even though I've never had a late payment in my life.

But you went bankrupt and about a year later you're financially free.

You would go bankrupt in a hurry if you were just running down to the courthouse steps and blindly plopping down a half a million at a time.