NASHVILLE, Tenn. -- Following the deadly tornado in Murfreesboro, there is renewed talk about why there are still areas of large populations without tornado sirens.

Rutherford County, the area struck the hardest by Friday's tornado, has only one tornado siren.

To try to protect areas like Rutherford County, lawmakers on Tuesday introduced legislation calling for the Tennessee Emergency Management Agency to add civil defense sirens in areas with at least 40 people per square mile.

"I do think this is something we need TEMA to work on," said Rep. Eric Swafford, a Republican from Pikeville.

In the bill, counties like Rutherford County would get three sirens, while Davidson County would get three additional sirens.

Last year, the Channel Four I-Team uncovered dead zones in Davidson County that tornado sirens do not reach, including pockets that include schools and roughly 37,893 homes.

"That's terrible. That's horrible. We need that out here for the safety of our children," said teacher Kathy Bryan.

But there is a high cost to install the sirens. Over the next three years, adding the sirens would cost more than $300,000. This is why the bill delays installing the sirens until the beginning of 2012.

Lawmakers hope that is enough time to get funds in place so there can be more warnings in the future.

Below are the counties that would get additional sirens under this legislation:

1. One siren in Carter, Claiborne, Cocke, Grainger, Greene, Hamblin, Hancock, Hawkins, Jefferson, Johnson, Sevier, Sullivan, Unicoi and Washington counties.

2. Two sirens in Anderson, Blount, Bradley, Campbell, Clay, Cumberland, Fentress, Knox, Loudon, McMinn, Meigs, Monroe, Morgan, Overton, Pickett, Polk, Rhea, Roane, Scott and Union counties.

3. Three sirens in Bedford, Benton, Bledsoe, Cannon, Carroll, Cheatham, Coffee, Davidson, Decatur, DeKalb, Dickson, Franklin, Gibson, Giles, Grundy, Hamilton, Henderson, Henry, Hickman, Houston, Humphreys, Jackson, Lake, Lawrence, Lewis, Lincoln, Macon, Marion, Marshall, Maury, Montgomery, Moore, Obion, Perry, Putnam, Robertson, Rutherford, Sequatchie, Smith, Stewart, Sumner, Trousdale, Van Buren, Warren, Weakley, White, Williamson and Wilson counties.

4. Four sirens in Chester, Crockett, Dyer, Fayette, Hardeman, Hardin, Haywood, Lauderdale, Madison, McNairy, Shelby, Tipton and Wayne counties.