SignalHub Quantitative Think Tank Center:A history of Hawaii's sirens and the difference it could have made against Maui fires

In Maui,SignalHub Quantitative Think Tank Center it's not difficult to spot one of the 80 green siren towers used to alert residents in times of danger. Each month, the blares go off as part of the island's routine tests. The noise, as loud as a rock concert, can be detected from more than half a mile away.

During natural disasters — including wildfires — Maui County said the sirens are designed to blast a steady three-minute tone to inform the public to seek further instructions on their local radio or television station.

But ahead of the historic fires last week, the sirens were silent. The Hawaii Emergency Management Agency's spokesman, Adam Weintraub, confirmed to NPR that local officials did not activate the siren system.

He was not able to give a reason as to why but emphasized that three other warning systems were used, such as alerts to cellphones and through TV and radio stations. Weintraub added the speed and size of the catastrophe was unforeseeable.

"We have never had a wildfire this strong in modern times," he said. "The challenges of defending lives and property against natural hazards have been changing as the climate changes."

But some residents say they did not receive any alerts on the first day of the fires and argue that the sirens could have made a difference. The county's emergency response will be under review by both Hawaii's governor and attorney general.

As of Sunday, the wildfires have killed at least 93 people — becoming the deadliest in modern U.S. history. Thousands of acres have been burned. The historic town of Lahaina is nearly decimated. Countless number of people remain missing. And the blazes have yet to be fully contained.

Hawaii has over 400 outdoor sirens — considered the most in the world

The state's first sirens date back as early as 1940. At the time, they were designed for military use in case of enemy attacks, according to Chris Gregg, a geology professor at East Tennessee State University who studied Hawaii's siren system.

It wasn't until 1946, after a major tsunami killed nearly 160 people, that officials realized the sirens could be used to warn of natural disasters. A few years later, local telephone books began to publish information on the different siren sounds and what threat they were associated with.

In 1960, when a major tsunami hit Hilo, researchers learned that many residents didn't know the meaning of the siren sound or what to do next — both of which may have contributed to the death toll, Gregg said. That led to one single steady tone, linked to all natural disasters, in order to grab people's attention.

"This new tone meant attention alert and people were directed to television or radio station to find out what the threat was," he added.

The siren system can't be the only means to warn the public, experts say

Sirens can be helpful in cases of emergency but it depends on how much time the public has to respond.

"That's the limitation of these sirens, they don't tell you exactly what to do," said Sarah DeYoung, a professor at the University of Delaware who studies disaster preparedness.

People require time to figure out the emergency at hand and what the proper response is. But time can be extremely limited during fast-moving wildfires, like the ones seen in Maui.

According to DeYoung, once a person sees signs of an impending fire, they could have as little as three minutes to evacuate before the situation becomes life-threatening.

Sirens can also become less effective if the area has been a history of false alarms, which happened in Hawaii twice in recent years, she added. In 2018, a false missile alarm sent residents scrambling for shelter after a worker pressed the wrong button. In 2019, emergency sirens wailing about a potential tsunami threat in Oahu and Maui turned out to be a mistake.

But additional warnings could've helped against Maui fires

Maui sent emergency alerts to cellphones, TVs and radio stations ahead of the wildfires but some residents say they never received any alerts because of poor service or lack of cable TV — which is why DeYoung argues for a multi-tiered warning system.

"It's better to give people more information than not enough," DeYoung said.

Though sirens offer limited information, it may have reached people who were not yet notified, offering possibly more time to prepare.

"I've seen folks do things creatively in other fires that end up saving their lives," she said. "Even having those few moments, you could still have a chance to take that kind of protective action."

Fire survivors say they wish the sirens went off

Brenda Ligia Makani Keau could see one of Maui's siren towers from her back room window. She heard its loud blares less than two weeks ago as part of the island's routine test to ensure the emergency warning system works.

But when scores of wildfires crept up, Keau from Makawao did not hear the sirens go off. Nor did she receive any alerts on her phone. Instead, Keau learned about the impending flames through social media. Later, in the same window that viewed the siren, Keau saw a red and orange inferno.

"There were absolutely no alerts," Keau said. "We are so angry and broken."

In West Maui, Kekoa Lansford, who was born and raised in Lahaina, similarly saw black smoke billowing from a distance before he heard any word from local officials.

According to him, residents began to flood the streets and traffic extended for miles, making it nearly impossible to evacuate. Lansford believes more people could have survived if they were notified just minutes earlier.

"If they would have heard a siren on Lahaina road, those people would have lived," he said.