Recreational Vehicle Lpg Tank Valve/gauge problems of the 2004 Toyota Corolla

Without any indication of a potential problem, my car lost complete power while driving it. In addition, my speedometer was stuck on 50 (I just got off the interstate & was going residential speed), my gas gauge reflected I had a full tank (I actually had a half of a tank) and my temp gauge said my engine was completely cool. I don't know what caused this to happen, but I'm lucky that it did not happen to me while I was on the interstate! let me clarify the facts here- total power loss while driving, steering wheel locked up, gauges - including the speedometer- while at a complete stop were stuck on inaccurate readings, no indication of an issue prior to it stalling! (prior to the car dying on me- headlights and interior lights were bright, radio worked, gauges were accurate. There was no loud noise when this happened, it is not the timing chain, the starter and battery are brand new, there was no hesitation and no trouble when starting it up. ) I have not been able to get the car to start since. Did not respond to a jump. From my understanding, there should have been some order in which power is lost - example radio first- dimming lights, etc. Before power is lost to the entire car while driving.