How can I tell if my break line is broken?? on 1991 Buick Riviera

I stopped kind of hard and heard a loud pop and right away my break pedal went to the floor. it will still stop but it goes all the way down??? What should I do?

2 answers
If your brake line broke somewhere you will find brake fluid pouring out somewhere. Suspect this may be the master cylinder that gave out.
or possibly a brake caliper over extended inself. look for a large amount of fluid.