I woke up to no hot water and the pipes were not frozen. We assumed the propane was empty, but I never checked the gauge outside. I ordered it and it is due to arrive today.
However................
Ha ha! Last night we check the gauge and found it was still 10% full and that one of the kids knocked the temperature dial off the hot water heater (breaking it and causing the flame to go out). We can all enjoy hot showers today. The kids have learned to stay away from the hot water heater now