"I have absolute confidence in Nalcor," she said of the Crown-owned corporation Nalcor Energy. "I have absolute confidence in Newfoundland Power."
And Dunderdale said she also trusts in the provincial Public Utilities Board to review the power failure that, at its peak Saturday, affected 190,000 customers in the province of 527,000 people.
Opposition Liberal and NDP leaders have called for a more formal inquiry but the premier brushed off such demands.
Her Progressive Conservative government also deflected accusations of mismanaging power supply amid increasing demand.
Dunderdale shot back at such critics Monday. She said her government has warned for years about rising power needs as it promoted the $7.7-billion Muskrat Falls hydro project now under construction in Labrador.
Nalcor President and CEO Ed Martin blamed the most recent widespread failures on unusually bitter cold, high winds and heavy snowfall. He also cited a transformer fire and a malfunction at the Holyrood power plant — separate incidents that are still under investigation, he told a news conference Monday.
"We plan the system long-term. We have a very detailed asset management plan in place that recognizes the age of the assets and the quality of the assets," he said.
"We are putting the appropriate resources and maintenance and such into this equipment."
Frustrated residents who vented on social media and on local call-in radio shows said they weren't convinced.
By late Monday, the provincial government said fewer than 5,000 customers were still without power though that could fluctuate, and that rotating outages had wound down. But it urged consumers to conserve energy where possible to help stabilize a still vulnerable system.
Eastern Health, the province's largest health authority, also cautioned people about carbon monoxide poisoning from generators, snowblowers, engine exhaust and propane appliances. It said in a statement that one person has died and eight others have arrived with related symptoms in emergency departments since Saturday.
All schools throughout the island, including Memorial University and the College of the North Atlantic, were shut down until Wednesday as a result of the disruptions.
Newfoundland Power president Earl Ludlow said Monday that crews made strides to restore power after residents and businesses were told a day earlier to conserve energy.
"I know it's frustrating, I know it's difficult," Ludlow told a news conference. "But I will also say that the plea for conservation did show up very quickly."
Planned, rotating blackouts started Thursday evening as utilities struggled to keep up with demand after frigid temperatures gripped the island.
On Saturday, a fire broke out at the Sunnyside terminal station after a transformer malfunction, triggering more outages as a blizzard slammed the island. Hydro officials are still investigating the cause, Martin said.
Then on Sunday evening, there was a flash in the switch yard at a power plant in Holyrood, plunging much of the island once more into darkness. Newfoundland and Labrador Hydro said crews were assessing what caused the issue at the plant about 50 kilometres southwest of St. John's.
Ludlow said once that problem is resolved, it will help stabilize the province's energy grid.
Dunderdale has said that a key benefit of Muskrat Falls is the subsea Maritime Link that would bring power from Labrador to Newfoundland then Nova Scotia, connecting the island to mainland energy sources when needed.
Still, she has repeatedly stressed that no electrical system is foolproof.
Many in the province were keeping a wary eye Monday on weather forecasts.
Paul Mackey, deputy city manager responsible for public works in St. John's, said there is some concern about flooding as warmer temperatures, rain and then another drop below freezing are expected.
With snow accumulations standing at about 140 centimetres in some places, Mackey said it's the most he has seen this early in the winter during his 22 years in public works.
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