With hundreds of thousands of New Jersey homes and businesses still without power in the wake of back-to-back nor'easters, Gov. Phil Murphy said Thursday he's ordered a state investigation into how utility companies responded to the winter storms.

Murphy said about 225,000 customers remain in the dark after the second storm slammed the state Wednesday -- down from about 350,000 at the height of the nor'easter.

About 17,000 are still powerless since the first storm last Friday.

"That is completely and wholly unacceptable," Murphy said during a news conference at the State Police compound in West Trenton. "You can imagine how they're feeling."

Murphy said he's instructed the state Board of Public Utilities -- which regulates the private power companies that service New Jersey -- to examine "what went wrong" and if "all preparedness measures were taken."

"My gut tells me they were not," the governor said. "And if they've not been, that is entirely inexcusable."

Murphy also announced there will be hearings in areas served by Jersey Central Power & Light, the company with the most outages.

In addition, BPU President Joe Fiordaliso said all utilities based in New Jersey must have their crews in state until power has been restored to all customers.

Murphy said he and Fiordaliso held a conference call Thursday with the heads of the four companies that provide power in the state: JCP&L, PSEG, Orange & Rockland, and Atlantic City Electric.

The governor said he and Fiordaliso expressed "deep frustration -- frankly, it turned from frustration to anger on my part -- at the uneven preparedness and uneven response."

Gov. Phil Murphy holds a news conference Thursday at the New Jersey State Police compound in West Trenton.

Murphy said JCP&L has 125,000 customers still without power but does not have a timeline yet for when all electricity will be restored.

PSEG has 80,000 customers without service and is projecting power to be back as soon as midnight Saturday.

Atlantic City Electric Company has 8,000 and is expecting power as soon as midnight Friday.

Orange & Rockland has 20,000 but no timeframe yet.

Murphy said other than schools, police stations and hospitals, the 17,000 JCP&L customers without power since Friday "will be prioritized."

Some Republican state lawmakers on Thursday called for Murphy to activate the National Guard to help the state recover.

"All available resources should be made available to assist residents and businesses," state Assembly Minority Leader Jon Bramnick, R-Union, said in a statement.

Assemblyman Kevin Rooney, R-Passaic, said it's needed because "clearly JCP&L isn't equipped to handle these outages."

Murphy added that "JCP&L's apparent lack of readiness remains a major issue that must be and will be looked at further."

Doug Colafella, a spokesman for JCP&L, said: "Right now, our focus is on restoring our customers."

"When that job is done, we'll cooperate fully with any investigation," Colafella added.

PSEG spokeswoman Karen Johnson said the company will work with Murphy and the BPU to "determine how we can enhance our storm hardening and response on behalf of our customers."

Murphy said JCP&L operates in "some of most wooded and rural areas of the state" and that winds, downed trees, and blocked roads have made restoring power difficult.

"But that's five, six days ago," he added.

Fiordaliso said there were "steps" instituted after Hurricane Sandy that utility companies must take to prepare for storms, and part of the investigation will focus on if they were followed.

"If they have not, they'll be held accountable for it," the BPU president said.

Because the utilities are private companies, the state does not have a direct hand in restoring power. But the BPU can put pressure on the companies and punish them.

Asked what punishment they could face, Murphy said it's "too early to speculate."

Fiordaliso said the BPU can order the companies to perform certain tasks and then follow their progress.

Murphy said the state wants to make sure the state and utilities are "better prepared" for the next storm.

For Murphy, the storms were the first major weather events since he took office Jan. 16.

"You live and you learn," he said. "We want to be self-critical and look in the mirror and say, 'What could we have done better?'"

State Police Superintendent Patrick Callahan said there were 715 car accidents as a result of Wednesday's storm, though none of them were fatal.

Murphy said there appears to be one death related to the storm: a man who died in a burning car Thursday after driving his vehicle around a barricade in Franklin Lakes and striking a live power line that had been knocked down.

Asked why there was so much trouble with stalled and abandoned vehicles, Murphy noted there were 149 trees down on state and interstate roads.

"We had pleaded with people to stay home," Murphy said. "The fact that it rained longer probably lulled people into thinking this was not what they thought it was gonna be."

Murphy said his state of emergency declaration stays in effect until at least the end of Thursday night.

He also stressed that melting snow is expected to turn to ice as the temperature drops overnight.

"If you're going out after dark, please, please, please be careful," Murphy said.

Jersey digs out after 2nd winter nor'easter 70 Gallery: Jersey digs out after 2nd winter nor'easter

Brent Johnson may be reached at bjohnson@njadvancemedia.com. Follow him on Twitter @johnsb01. Find NJ.com Politics on Facebook.