Lahaina resident Cole Millington, his dog and a go bag at his side, was already behind the wheel of his truck late Tuesday afternoon when an emergency alert appeared on his phone.

"There wasn't really an evacuation notice for us," Millington said. The real warning, he said, came from the "huge plume of black smoke" in the sky over Lahaina.

Millington and his roommates had seen enough. They fled as wildfires began to scorch large swaths of the Hawaiian island of Maui, killing at least 80 people and destroying Millington's home among hundreds of other structures.

The cell phone alert "was useless," said Millington, who owns a hot sauce company in the historic town. "We have tsunami warnings that I think should have been utilized... So many of us ... felt like we had absolutely no warning."

In fact, the state's vaunted integrated outdoor siren warning system -- the largest in the world, with about 400 alarms -- was not activated during the fires, according to Hawaii Emergency Management Agency spokesperson Adam Weintraub.

On Maui, the second largest island in the Hawaiian archipelago, there are 80 outdoor sirens to alert residents to tsunamis and other natural disasters. They sat silent as people fled for their lives.

"Nobody at the state and nobody at the county attempted to activate those sirens based on our records," Weintraub said in an interview.

"It was largely a function of how fast the flames were moving," he said, referring to the failure of emergency management officials to trigger the sirens. "They were trying to coordinate response on the ground, and they had already issued these other alert systems."

The layers of the emergency warning system that were activated included mobile phone alerts and messages on televisions and radio stations, Weintraub said.

"On my cell phone, we had warnings of strong winds and possible fires," said Allen Vu, a Lahaina resident whose home was lost in the fire, along with the restaurant where he worked.

"But no real ... warning like the Amber Alerts or those storms that we would normally get that would vibrate and make loud noises from our phones. We didn't get any of that. There were no sirens."

Vu and Millington are among the residents of Maui questioning the effectiveness of the emergency warning system employed as the wind-whipped fires spread rapidly across Lahaina and other parts on Tuesday. It would become the deadliest natural disaster in the state's history.

Hawaiians accustomed to siren warnings

Hawaii Attorney General Anne Lopez will lead a comprehensive review of the emergency response with the goal of "understanding the decisions that were made before and during the wildfires," her office said in a statement.

Rep. Jill Tokuda, a Democrat, said the state "underestimated the lethality, the quickness of fire" and that the redundancies in the emergency alert system failed.

Hawaii residents have long been accustomed to the monthly tests of the outdoor siren warning system.

"We rely on that emergency alert system to keep us safe from a number of things," she told CNN Saturday. "You think tsunamis. You think other types of emergencies like wildfires. That should have been our first line of defense. Unfortunately these days the alerts come on our cell phones. But we also know that there was no cell phone coverage."

While Maui's warning sirens were not activated, emergency communications with residents were largely limited to mobile phones and broadcasters at a time when most power and cell service was already cut.

"We don't see any indications that Maui did anything wrong," Weintraub said.

"Maui County faced a challenging, rapidly changing situation, and I think they did everything possible to save lives. And they still are," he added.

Karl Kim, executive director of the National Disaster Preparedness Training Center at the University of Hawaii, said that, in addition to the sirens, Hawaii has "multiple channels and sources of information -- from the media, social media, from neighbors, friends and family and other means of communications."

"Clearly more work needs to be done to understand the science of wildfires, how they spread and what can be done to improve detection, alert, and warning systems," he told CNN via email.

"People often seek confirmation that the threat is impending, they may wait to see the flames or smell the smoke or witness others evacuating before taking action. Unfortunately the delay with a fast moving fire may have deadly consequences. Even if people receive the warning, they may not understand it, nor have the means or mobility to evacuate. "

'Nobody saw this coming. Period.'

The fire spread with such speed that many people left their homes immediately with little notice from authorities, Maui County Fire Chief Brad Ventura said. It was "nearly impossible" for emergency management officials to make timely evacuation notifications, he said.

"What we experienced was such a fast-moving fire through the neighborhood that the initial neighborhood that caught fire, they were basically self-evacuating with fairly little notice," Ventura said.

Said Maui County Police Chief John Pelletier, "Nobody saw this coming. Period."

Fueled by a combination of strong winds and dry conditions -- and complicated by the island's geography -- the blaze virtually destroyed the tourist and economic hub of Lahaina and left authorities searching frantically for the missing.

Gov. Josh Green said the death toll could climb. It is unclear how many victims could still be in the charred ruins of what was once a whaling port and fishing town on the west coast of Maui. Some fatalities occurred "out in the open as people tried to escape the fire," the governor said.

As the fires spread on Tuesday, power and most communication -- including 911 and cell phone service -- were cut off. Communication was still compromised Saturday due to severed lines. Many people reported not hearing from their loved ones in days. Officials resorted to updating the public via radio stations, as well as posts on the county's website and social media pages.

Weather service gave residents heads up

Despite warnings, residents and authorities seem to have been taken by surprise.

"We had a few days lead time about the weather conditions," said Clay Trauernicht, an assistant specialist who studies tropical fire at the University of Hawaii at Manoa.

On Sunday, the National Weather Service in Honolulu issued a "fire weather watch" for the state: "Strong and gusty winds, combined with low humidities ... may lead to critical fire conditions across leeward areas over the coming days."

Early Monday morning, the weather service issued "a red flag warning" as dry lands, coupled with "strong and gusty easterly winds and low humidities," create "critical fire weather conditions."

"Any fires that develop will likely spread rapidly," the warning said.

May Wedelin-Lee, who also lost her home in Lahaina, said the wind shifted and smoke and flames overtook her community so quickly early Tuesday afternoon that people had less than 10 minutes to prepare.

"People were crying on the side of the road and begging," said Wedelin-Lee, a 20-year resident of Maui.

"Some people had bicycles. People ran. People had skateboards. People had cats under their arm. They had a baby in tow. Just sprinting down the street."

Hours earlier, at 9:55 a.m., Maui County posted a seemingly optimistic update on the Lahaina fire:

"Maui Fire Department declared the Lahaina brush fire 100% contained shortly before 9 a.m. today," the county said on Facebook Tuesday.

About an hour later, the county updated residents on another wildfire burning:

"Kula Fire Update No. 2 at 10:50 a.m.: Firefighter crews remain on scene of a brush fire that was reported at 12:22 a.m. today near Olinda Road in Kula and led to evacuations of residents in the Kula 200 and Hanamu Road areas," the county said.

By Tuesday afternoon, another wildfire became an increasing threat:

"With the potential risk of escalating conditions from an Upcountry brush fire, the Fire Department is strongly advising residents of Piʻiholo and Olinda roads to proactively evacuate," Maui County posted at 3:20 p.m.

Less than an hour later, it said, "The Fire Department is calling for the immediate evacuation of residents of the subdivision including Kulalani Drive and Kulalani Circle due to an Upcountry brush fire."

Later, the county said the Lahaina fire had resurged.

"An apparent flareup of the Lahaina fire forced the closure of Lahaina Bypass around 3:30 p.m.," Maui County posted at 4:45 p.m.

By 5:50 p.m. Tuesday, there were "multiple evacuations in place for Lahaina and Upcountry Maui fires," the county reported.

'A wake up call'

Last year, Hawaii officials released a report ranking the natural disasters most likely to threaten state residents. Tsunamis, earthquakes and volcanic hazards were featured prominently. But the state emergency management agency report described the risk of wildfires to human life as "low."

Hawaii officials underestimated the deadly threat of wildfires even as they acknowledged a lack of necessary resources to mitigate them, according to a CNN review of state and local emergency planning documents that show how ill-prepared the state was for the disaster.

The state emergency management agency's public resources webpage includes clear, bullet-point recommendations of what residents should do in a hurricane, tsunami, flash flood or earthquake. At the bottom of the page there are two short paragraphs about wildfires -- with no similar advice on ways to stay safe.

In 2018, as Hurricane Lane approached Hawaii, bush fires scorched a total of 2,330 acres in Maui. The next year, fires in Maui consumed about 25,000 acres.

"This is a wake up call for not just Hawaii but also other communities throughout the country that need to invest more on preparedness and training and education for wildfires and other hazard events," Kim said. "More work needs to be done in understanding wildfire risk and how we can better mitigate the harm and reduce the tragic loss of lives."

The Maui fire is the nation's deadliest since California's Camp fire, which killed 85 people in November 2018.

Brock Long, who as former Federal Emergency Management Agency administrator from June 2017 to March 2019 coordinated the response to more than 100 wildfires, said the unpredictability of fires means decisions need to be made quickly.

"Initially, it looks like Maui County did a pretty proactive job of putting the word out that these fires are dangerous and to evacuate," he said. "And when I look at some of the initial time frames that were there, the question is, 'Did people heed the warning?'"

‎Maui photographer Rachel Zimmerman, who lost her home, described the chaos and uncertainty as the fires approached.

"The wind is just howling. We're seeing roofs that are flying off," she recalled. "And people are just kind of standing around in my condo complex, neighbors, looking: What do we do? We heard there was a complete gridlock and we weren't going to be able to get out but we knew we had to try.

"There were people jumping into the ocean, swimming to boats to try to escape the fire. There were people on the ground, crying and unsure where to go and not able to breathe because of the smoke. It's just unbelievable to know that so many people have been lost and we don't know where they are."