On September 28th I was driving along the highway, went to take an exit, and the brake pedal was locked. I experienced a loss of braking, hard brake pedal and increased stopping distance. In order to get the car to stop, i had to put the car in neutral and coast into a ditch/grass. Before the brake failure there was no instrument cluster malfunction lights illuminated or any warning of imminent failure of the vehicles braking system. A mechanic has informed me that the vehicles brake vacuum pump is to blame and that it needs to be repaired immediately. This part suddenly failing with no warning caused a complete brake failure within the car and posed a risk of injury or death to me and others.