NASHVILLE, Tenn. -- Not everyone heard the sirens warning of Tuesday night’s devastating storms, because some areas don’t have them.

Video - I-Team: Many Counties Lack Tornado Sirens

The I-Team found that many of the tornado-ravaged areas of the state don't have tornado sirens and that some heavily populated areas have only a few.

An I-Team analysis of middle Tennessee counties shows that areas with the worst damage and other counties with big populations have few or no sirens.

In Sumner County, where seven people have been confirmed dead, there is only one siren. In Trousdale and Macon counties, where 17 people have been confirmed dead, there are no sirens.

In tornado-prone Madison County, where two are dead, they have 47 sirens, but officials said it needs 22 more to cover the entire county.

While there are debates about how often sirens save lives, there's still a great disparity across our region.

In Rutherford County, one of the fastest growing regions in the country, there is only one siren for the county’s population of 228,829. In contrast, Williamson County, one of the state’s wealthiest counties, has 53 sirens for its 160, 781 residents.

"People that are caught outdoors, it's a lifesaver,” said Kevin Penney with the office of emergency management.

It's also a struggle for counties with booming populations. After a 1998 tornado, Davidson County got 70 sirens, but the county hasn't had a new siren in five years even though its population has grown by 33,000 people since 2000.

Emergency management officials emphasized that the 70 sirens were put in public places designed to warn people outdoors, not inside homes.

“Sirens are meant for outdoor use and outdoor warning and notification,” Penney said.

But that’s not good enough for victims who were inside when the storm hit.

"We’d hear it. If the TV went off, we’d still hear the siren. If the electricity had went out an hour before the tornado hit, we would have heard the siren,” said Amber Burrow.

While emergency management officials encourage people to watch the news and buy weather radios, they know that for many people, hearing that siren is their first sign that trouble is heading their way.

Tornado sirens can cost up to $20,000.