While sirens can help in areas with shaky cell service, experts say officials also need to consider alert fatigue and provide education on what to do in an emergency.

In the wake of the deadly flash floods in Texas, state leaders are exploring whether to install more flood warning sirens. Such sirens can save lives if they're part of a larger warning system.

The cost of repair or replacement has been estimated as high as $20 million, and cell phone alerts, while far from a perfect warning system, is the primary technology the city relies on.