First of all, you're not doomed to die because you have broken legs.
Of course, you could die if you don't get help from someone. You could get gangrene, or some other nasty infection, that you can't cure without knowledgeable help and chemical treatment. You might not be able to get up to feed yourself, or clothe yourself, or go to the bathroom. You might not be able to go to work, so you might not be able to pay for the rent or the food you need to live. You might not be able to go out to seek pleasure or human contact; you might need others to come to you.
But so long as someone can give you these things, your broken legs will heal. And you can go on walking again.
Some people get broken legs in an accident. Some people get broken legs because someone else wanted to break them. Some people get broken legs because they were born with them. Some people never get broken legs. But if you get them, broken legs hurt.
Lots of people disagree. Some people think that broken legs don't really hurt that bad (not as bad as their broken back, or their mother's broken neck, or their neighbor's broken arms). Some people think that you can walk with broken legs (unless you're just lazy or immature) and they will heal on their own in time. Some people think that there's no such thing as broken legs, and that other people just pretend to have broken legs for attention.
Most people don't notice broken legs anyway. People with broken legs have to say "Excuse me, but my legs are broken and I am very thirsty. Could you bring me some water?". There are a few people who look closely enough to see if someone has broken legs, though. These are the people that don't wait to be asked - they just bring the water because they know it's an easy thing to do (when you don't have broken legs).
If you ever get broken legs, you'd better find out first what people think about them before you ask them to help you. If you don't, they might not take care of you well enough and you might die before you have a chance to get better. And if you can't find anybody that will help you, keep yelling until the right person comes. Don't give up when your voice gets tired, just take a rest then yell some more.
And remember, you're not doomed to die because you have broken legs.
What you should know about broken legs:
