The Bermuda is not dead but dormant this time of year as it is a warm season grass. I do not think using chemicals will kill it while it is dormant.

On two occasions I have killed two separate 2500 sqft areas of Bermuda during the growing season (summer). It is very difficult with chemicals. I have never heard of anyone successfully killing Bermuda (really killing it) organically. I would like to know if it can be done.

Well it has been tilled up so its broken up into many tiny pieces. I know this is like axing Mickey's broom - once the warm season starts, all those little pieces are going to take off. Would it be a nightmare to try and pluck them out of the soil once they get going for the season?

Some of those little pieces you are asking about picking out are several feet deep. What ever you don't get will spread.

Solarizing is your ONLY organic option.

You might be able to smother it with sand and mulch. Use at least two inches of both. Sand on the bottom and mulch on top. Then be sure to pull any sprouts you see.

aye aye aye ok thanks you guys!

Some people have attempted to smother Bermuda grass with newspaper and cardboard, much more effective then 2 inches of sand or a mulch material, and found that Bermuda, like Quack Grass, will simple grow through it. It may take a year or so but it returns.
Solarizing the soil might work but the temperatures also might not get high enough even just 4 inches down. Some sources suggest using two layers of clear plastic sheets. This from the university of California might be of some help.

Here is a link that might be useful: Soil Solarization