About three percent of people in Tulsa are in a gap between storm sirens. That doesn't sound like much, but it's actually thousands of people.
Now the city is working to expand their storm siren network and fill in those gaps.
Tulsa has 90 outdoor warning sirens, but emergency managers believe that's not enough.
Each siren - in good conditions - covers a square mile, but during a storm they can be hard to hear.
Roger Joliff controls the sirens, but it's up to the city to buy new ones.
“It's important to have overlaps with these sirens so you're sure you're warning people at the level you need to,” he said.
The city buys a handful each year to update the technology, but that's mostly done. The next step is adding more sirens to expand the coverage.
“We try to match the sirens to where the population growth is and as the city expands into these areas, we try to cover that area with sirens,” said Joliff.
They'll be added to the system next year if they're included in the budget.
Each siren cost about $30,000.
The flood sirens haven't been used for years but the tornado sirens sounded for more than an hour during the Sand Springs tornado.
Did it save lives that day and that moment? I don't know but I'm sure glad it was there,” Joliff said.
Even though there are many ways to get a warning now, Joliff believes Tulsa should finish building the siren system so that people outdoors will get a warning they might not get otherwise.
"The sirens are a last moment of warning. It's going to go off as a tornado is forming or already on the ground and you have the opportunity with other technology to get notice earlier and better plan for your family," he said.
Emergency managers said it would take about 15 more sirens to fill all of the gaps outdoors.
They also recommend people use weather radios and mobile alerts to get warnings.