HONOLULU (KHON2) — Maui’s biggest power outage in recent history knocked out electricity for most of the island, shuttering schools and leaving residents, workers and businesses looking for answers.

The last to get their power restored came right around 2 p.m. today, and the cause we found out — a substation short circuit — which has many wondering how one glitch could knock out power nearly islandwide.

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While most of the Valley Isle was sound asleep, a power outage wave spread across the island starting around 2:45 a.m. taking out power for 65,000 out of 70,000 Hawaiian Electric customers on Maui.

“Very unusual to have this big of a widespread outage affecting the entire part of the island,” said Hawaiian Electric spokesperson Shayna Decker.

Fourteen public schools were closed for the day in West, Central and Upcountry Maui. The water department asked customers to conserve because wells, treatment and distribution rely on power, and many county services were paused. Residents and businesses were left scrambling.

“We saw parents frantically waiting to hear what was happening with their child’s school,” said Pamela Tumpap, president of the Maui Chamber of Commerce. “Cafes couldn’t serve breakfast. We’ve heard service businesses trying to redeploy workers where there was power. We’ve heard that businesses had to change their day in and need to call employees in and of course work with their employees who needed to stay at home with their children because the schools were closed.”

The morning drive was a bit stressful.

“Thanks to the men and women of Maui Police Department who were out there at the traffic intersections directing traffic,” said Mayor Mike Victorino. “That’s not easy when you don’t have those traffic lights.”

The island hasn’t seen a power failure this widespread in years.

“We really needed to look back,” Decker said, “and it was actually October 2017, there was an outage about 66,000 people that were affected on Maui, and that was due to lightning.”

But this time, weather wasn’t to blame.

“There was a high-voltage short circuit that occurred at our Maalaea substation,” Decker explained, “and so this triggered some of the generating units to go offline, so we’re looking at the cause of what happened and what caused that short circuit.”

“We all started feeling like, okay, this really is kind of a disaster now, because while doesn’t feel like a disaster because the weather isn’t a problem, we started realizing that everything planned for today immediately had to shift,” Tumpap said.

Always Investigating asked Hawaiian Electric: Where were the backups? Why would a short circuit in one substation be able to take almost the whole island down? How are they going to prevent this in the future?

“That’s what we’re really looking into, you know, why was it this widespread?” Decker said. “This morning, the priority was — get the power, get the lights back on for everybody that was affected. And so now, our group and our crew are really looking into assessing that cause and looking at preventative measures to see what was the instigation of this today. And, you know, we really hope to report back and find what was this so we can actually prevent it and make it more reliable as we go forward.”

“They have assured me that they’ll give me a report in the next 30 days, on why and what happened, and how they’ll better protect the grid in the future,” Victorino said.

According to Hawaiian Electric, the problem doesn’t appear to be connected with the large Maalaea generating units themselves, some of which are obsolete without replacement parts available.

“We’ve said and reported on certain issues with the equipment for those generating units that are at Maalaea,” Decker said, “but today’s incident is not connected to that issue of the supply chain and having the supply parts for those generating units.”

The last customers came back online around 2 p.m.

“For many businesses, there was revenue loss during that period of time, and I know some in the food industry also have to look at how many hours the refrigeration was out and what that means for the food storage, and others had to delay opening,” Tumpap said. “So it’s going to have a significant impact.”

Residents and businesses with losses can file claims with Hawaiian Electric.

Not all areas were affected for as long as others.

“We’re talking approximately 11 hours of power problems throughout my county, but by noon, nearly 64,000 of the 65,000 customers had their power restored already,” Victorino said, “So it’s incredible that they were able to get back considering it’s an islandwide outage, they got it back up and running. I know of where I live, it was within two hours of the first outage, our power was restored.”

Meanwhile, the power company said it’s committed to solving this mystery and making cleaner, more reliable power.

“We recently filed five-year resiliency plans to harden our electrical grid across the island,” Decker said. “It’s always going to be safety and reliability for our customers.

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“If we don’t make those substantial changes within our grids, and our power sources, and make ourselves more resilient and sustainable, we’re going to have problems like this time in and time out,” Victorino said.