It's dead, Jim

2 years ago a contractor regraded my front yard, I found that the soil was full of sand, debris, and crap, and I've spent the past year or so trying to take control of the lawn.

The patch in these photos was dead last fall. The cleanly delimited lines of the dead spot made me think something was wrong with the soil. I dug up the top 3-4 inches, threw it away, and replaced it with a combination of soil from elsewhere in the yard and some top soil; then seeded, fertilized, covered, and watered.

The grass sprouted but grew in very thin and weak, like hair, as you can see. I thought maybe I had just put down too much seed. It did grow though, and up until about a week ago was not doing great but was alive.

We had our first warm day 90+ this past weekend and the grass immediately died, you could almost see it wilting. The first picture was taken Monday, the 2nd one just now. It's completely dead.

The plugs you see are from my attempt at hand-aerating it, the ground is so hard and compacted that I could not get deeper than about an inch. This isn't really that unusual around here, all of the soil is compacted, but not all of the grass is dead. I will try to aerate again after it rains.

Any ideas what may have gone wrong? I have patched and reseeded about 6 other spots around the yard and followed the same process with the same seed (Jonathan Green Black Beauty blend) and did not have any other problems.

At this point I'm not sure I can seed it with July approaching, I might just have to look at a dead spot until I can redo t in the fall.