Found out after work why Dad had a flat yesterday, somehow, the tire valve back out nearly all the way out of the stem on the right rear.........while it was sitting in the lot at the nursing facility Mom is currently in....... Luckily, since he had to take it to a local NTB since he couldn't find his tool for that, they actually fixed it for free! They also offered to put the tire back on, but he didn't want to press his luck and risk getting charged for that, so he brought it home and swapped it back around himself.