In the US, what happens if you sustain a life threatening injury and you don't have insurance?

You still have to pay for the bankruptcy. I don't know exactly how it works because I've never declared it, but it's not free to go bankrupt either. In American Capitalism they will screw the poor people every way they can.

There has to be some form of bankruptcy, isn't there?

When you declare bankruptcy, you're basically going to the courts and saying, "Look. I don't have the money or the income to cover all my debts. I need help." If the court agrees, they'll force all your creditors to come to the table to negotiate.

The court determines what assets you can keep and determines the best way to divvy up what's left. Usually you keep your house, car, and basic necessities but that can vary. Some states don't protect the house or car but even then the court will consider if it's cheaper or better for you to keep either of those than to go rent a new house and take alternate transportation.

Then they look at your income and decide what you can afford to pay over time. If your income is too low, they may consider all your debts settled at that point. Otherwise, they may set up a payment plan for so many years and consider you even after that.

Medical debt is the number one reason for bankruptcy. To twist the knife a bit, people who have large medical bills are often in a physical condition that makes it hard to work. About 2/3 of all bankruptcies, or 530,000 families annually, cite their medical bills when filing. After that is mortgage debt (45%), living beyond their means (44.5%), providing help to friends and family (28.5%), student loans (25.5%), and divorce (24.5%).