First thing you should try and do to slow down your vehicle when your brakes go out remove your foot from the gas pedal and try and pump your brakes up by pumping the brake pedal at least 4 times.
If your brakes don't build up pressure by then, then you'll need to try the emergency brake. When applying the emergency brake then do it slowly and not fast.
Applying the emergency brake too fast could cause you to roll the vehicle so just apply the emergency brake slowly to help bring the car to a gradual stop.
If your car will not stop then you might have to turn towards an open field if one is near the highway or road you're on.
Even if you have to plow through someone's fence it's okay to do so as long as it's not gonna put you in more harm.
But either way you could be in harm without your brakes so you have to resort to anything you can think of and quick.
When my brakes went out one time I had no choice but to turn off the road and drive through a barbed wire fence and go into someones field.
It was either that or crash into the back of a semi and the field was the much better option and you only have a split second in most cases to think about what to do.