We will see signs of the collapse before it happens. Perhaps a major nation goes down first, like a EURO collapse or major China currency inflation.
If the problems are all US centered, we will see California crashing hard before anything else. If you live in California, it's gonna be rough. Welfare will run out of funding, the rich will evacuate, you will be left with millions of people without money, food or gasoline. The landlords that want to stay will try to evict people that formerly got housing assistance and no longer do. Same with everyone that gets laid off from businesses the rich abandoned.
Home owners will see massive value corrections from the recent upswing. When there are not 100 cash buyers bidding up that million dollar condo it turns back into a 400k condo.
I don't mean to offend anyone living in California but the facts are:
1. Super Dense Population competing for resources
2. Very high paying jobs, at least Today.
3. Large number receiving state and federal welfare
4. Many wealthy people choosing to live there, but could go anywhere in the world to live.
So if you remove everything but #1, it gets ugly fast.
My advice, don't live in super dense high cost areas. Have diversified holdings, to include: Land, gold, guns, food storage, quality reliable vehicles, tools, cash, and if you still have money, stocks.