Brake Master Cylinder problems of the 2006 Mercury Mariner

The traffic light turned yellow, I applied the brakes which worked momentarily then released as the brake pedal went all the way to the floorboard. No warning lights illuminated in the instrument panel. Using the emergency brake I stopped short of blocking the intersection. Upon stopping it was determined that on level ground with the vehicle idling in drive and the brake pedal fully depressed there was not enough brake force to keep the vehicle from moving forward. Inspection of the vehicle revealed that the left (driver side) front flexible brake line had ruptured and that there had been a small amount of brake fluid lost from the master cylinder. This line is about 17 inches long with a metal sleeve in the middle where it is attached to the vertical strut for support. The rupture was at the top of this sleeve. While bleeding the brakes after the line was replaced, it was found that the low brake fluid sensor worked. Is this an unknown "safety feature" of abs? if it is, progress has brought us back to where an individual part can cause the same catastrophic failure as before the split system was introduced in the 1960s. I am the original owner of this vehicle. This has been reported to Ford motor company.