Clutch Pedal/linkage problems of the 2003 GMC Sierra 2500

I entered the truck stepped on the clutch pedal, shifted into reverse and started to ease the clutch out when the pedal went all the way to the floor board. The vehicle immediately chirped the back tires at no more than 950 r. P. M. 's and began to immediately go backwards towards another vehicle in my driveway. I quickly stepped onto the brake and stalled the vehicle to a stop. I then proceeded to look under the dash to see what had "popped" and found that I could see light throughout the firewall, as I moved the pedal up and down. I opened the hood to find that the black plastic flange that the clutch master cylinder mounts to had broken or shattered releasing the master cylinder therefore, completely disengaging the clutch. Had I not been quick to react, I would have struck another vehicle in the side causing extensive damage. Had I been in 1st gear when the failure occurred I would have lunged foward at the end of my driveway and off a 10' ledge straight down into my neighbors backyard, resulting in personal and property damage. This vehicle has only approx 104 thousand miles. This was a poor design and has failed in a very dangerous manner. This needs to be recalled immediately.