That's just weird! The picture is upside down until you click on it. Then it rotates right side up.

The problem is most likely improper watering, but I'd need more information...

Where do you live in FL?
What is your watering regimen (how often and for how long)? Did you follow a special watering plan for the first 3 weeks after the sod arrived?
Was the sod put down the day it arrived or did it sit on the pallets for a day or two?
Is the grass in the shade?
Is it possible there are large rocks or wood stumps under the soil right there?
Have you laid anything (including garden clippings) on the grass for a day or two at a time?
Was the sod rolled down after application?
Have you fertilized? If so, what did you use?
Have you used any insecticides, herbicides, or fungicides?

Thanks for replying, to answering your question. 1. I live in Orlando. The sod was place down on the same day. It was being watered for 5 min. Every zone and I believe it was everyday.
2. Once I did the closing and moved in I was told by OUC that watering was on Saturdays for 20 min. Every zone.
3. I set timer for saturday but sprinklers didn't turn on. Did a test and they weren't working once I reach the contracter my sprinklers were closed by the main valve. So my grass did go by these hot pass days without water.
4.I did water my lawn by hose once I notice the dark spot. Since it was getting worse...
5. I went to Home Depot and I spoke to a nice gentlemen who told me that my lawn needs fertilizer and since it was too hot I should usethe MILORGANITE Fertilizer and the B GON for bugs that I had eating my leaves of the shrubs and a black like hairy worm that fell right into my cement floor when we cut the lawn.
6. Before, putting down the fertilizer I used a spike aerator.
7. I called OUC to verify my watering days and its on Wednesday and Saturdays. So I got screw at first.
I just want to make that piece look nice again and I have no idea how to do it.
if you can give me any ideas, I will be totally grateful.

Thanks for the reply. Sorry I've been gettin' educated for my job and didn't bring a computer with me. Now I have one, so I can get back to the important things.

St Augustine is very easy to grow perfectly but much easier to grow wrong. By now you should realize that the grass is dead. It was from going completely dry with short little roots. But some of it will be alive. That grass which is alive can still recover and take over your yard.

Next time you can water, set out some straight sided cans to catch the water. I like cat food or tuna cans because they are the right height. Time how long it takes to fill those cans. That is your watering time. Forget all about 20 minutes unless that's how long it takes to fill the cans. All you need is the new time for filling the cans.

That day you watered and timed how long it took to fill the cans will be day 1. The next day you can water the grass will likely not need it, but do it anyway - you're trying to fix this. Water for half the time it took to fill the cans. Since you have new roots you have to baby them a little. So you're going to water for half your "normal" watering time, twice a week. This is just to get you started. After you do that for two weeks, see if you can water the full duration and skip the second watering day of the week. Your grass should easily (EASILY) go a full week with one watering if the grass is thriving. With your temps this time of year, once the roots and grass are established, it should go 2 full weeks without any water.

You do not need to water the completely dead areas. Just water the living grass and encourage it to spread back and refill the dead areas.

Always mow St Augustine at the mower's highest setting. There is never a reason to shorten this variety of grass. Having said that there are dwarf varieties, but yours doesn't look like a dwarf.

As for fertilizer to get you going, I would use nothing but organics until the lawn is up and filling out. Why? Because you can use them in any season, rain or shine, without any fear of hurting the grass. My favorite for now is ordinary alfalfa pellets (rabbit chow). Just drop a handful along every growing strand of St Augustine. It doesn't matter if you use too much unless you actually smother the grass in it.