Before he left town a week and a half ago, it was beautiful and green. Now every bit of it is dead. I watered it every other day and I have mowed it twice. I has been above 100 degrees most of the weekend and this week. Did you soak the lawn with each watering.
Fescue needs to be mowed as high as possible and thourghly soaked with each watering.
If the area is exposed to direct sun light the fescue may also have gone dormant. I have seen lush green lawns left for a week while the homeowner went on vacation only return to severe Brown Patch damage. The Brown Patch was active when they left town they just didn't know what symptoms to look for.