Gov. Phil Murphy, in Friday's update from state health officials on the ongoing novel coronavirus pandemic, said it's "when, and not an if" New Jersey will order all public schools closed — even as hundreds have taken the measure on their own. (See the list below).

"We are actively working toward the inevitability that every district will be closed for a prolonged period of time," Murphy said after announcing that the state's positive coronavirus cases had nearly doubled overnight.

According to the state data published by mid-day Friday, 354 New Jersey school districts — of more than 600 in the state — had already announced closures on their own. Of those, 215 were for professional development and staff training to prepare for extended home instruction. Forty-four were doing precautionary cleaning.

Another 90 were concerned about potential COVID-19 exposures, four were responding to confirmed exposures in their communities and 1 had a confirmed positive test.

But the governor stopped short of any universal order to close. He said the state and schools must make plans to provide home instruction, and to connect those who need it with free or reduced-price meals and other services normally obtained through schools.

"We cannot take that lightly, and we will not," Murphy said.

He said of 1.4 million students in New Jersey schools, 259,000 don't have smart devices that could be used for home instruction.

But Murphy said he expected a closure of all schools could happen "in a matter of days."

21 new cases: NJ total now at 50

The announcements came as state health officials announced 21 new presumptive positive cases of coronavirus, taking the state's known total up to 50. Three of those are 50 are described as "positives pending information." All positive cases are considered presumptive until confirmed by the Centers of Disease Control.

Data published Friday night by the Department of Health indicated the 21 new positive cases come from nine counties: five in Essex, four in Bergen, two each in Hudson, Middlesex, Monmouth, Morris and Passaic; and one each in Burlington and Ocean.

For Ocean County, that was its first presumptive positive test result. It had been announced that there was one presumptive positive in Mercer County, but that is not reflected in the data released. Also, there was one fewer case in Monmouth than had been cited at an afternoon briefing.

Health Commissioner Judith Persichilli said there are 80 persons under investigation at the state lab currently. She didn’t know how many tests are pending at the two commercial labs and two hospital labs in New Jersey. The state only receives information from them about positive test results.

"We have expected, at this point, more numbers than we have," Persichilli said.

The state's largest city saw its first positive case on Friday — a 41-year-old woman who lives in Downtown Jersey City. City officials say the woman was "proactive when she felt symptoms and initiated testing with her private physician." The test result was shared with the city's Health Department Communicable Disease Reporting Surveillance System. The city said seven other people have been tested with negative results.

Also in Hudson County, Hoboken on Friday reported its first positive case: a man in his 40s who is experiencing mild symptoms and is expected to recover. The Hoboken Health Department has been tracing people that the man has been in contact with.

On Thursday night, officials in Old Bridge said that a resident had tested positive and that the resident's child, who attends public school, also was showing symptoms. The news resulted in the late announcement that township schools would be closed completely on Friday and Monday as officials prepare to implement possible online and remote learning for the remainder of the week.

Long Branch also marked its first case Friday: a 39-year-old man who has been hospitalized at Monmouth Medical Center since Monday.

Dr. James Pruden, director of emergency medicine at St. Joseph's University Medical Center, is also among the latest cases, state officials said.

Persichilli said officials were looking into one death from a person who had not previously tested positive for COVID-19. Officials didn't provide many details about that case.

“There’s been no new deaths of a confirmed case," Persichilli said. "There is one that we’re tracking at this point in time, but we have not gotten the results back.”

New Jersey has just one confirmed coronavirus fatality — a 69-year-old man who had underlying health conditions.

Other steps announced Friday:

• Visits to nursing homes and other long-term care facilities would be restricted, expect for those visiting people at the end of life or in hospice, Persichilli said. All workers and anyone who comes in contact with patients will have to be tested.

• State officials said they're not prepared to do mass testing at this moment, but are making preparations. Persichilli stressed that mass testing is mostly useful to epidemiologists, because the course of action for anyone with symptoms — regardless of a positive result — is the same: Avoid contact with others and reach out to a health provider for possible testing. But "we are working on broadening access to testing in both private and public sector," Murphy said.

• The Motor Vehicle Commission will extend driver's license renewal deadlines for two months, for all licenses due by May 31.

• There are currently no plans to order casinos closed. More cases have been reported in north Jersey than south Jersey. Hard Rock Hotel and Casino announced earlier Friday it was canceling entertainment until mid-April.

• State officials have asked the federal government to extend their deadline for compliance with the federal REAL ID license program

• Murphy said all public utility shutoff orders have been voluntarily suspended.

• He said New Jersey has sought from the federal Department of Transportation flexibility that would help keep truckers able to maintain supply lines, including for resources that have been flying off shelves in New Jersey, like water and baby formula. It wasn't immediately clear from the governor's remarks what form that help would take

• The state is seeking federal waivers to make sure districts can retain access to lunch programs for students

• New Jersey is expecting a large shipment of medical supplies from the federal government of respirators, face masks and face shields. "This is not remotely the entirety of our ask of the federal government," Murphy said, adding he hopes further shipments will be on the way.

Long-term school closures as of March 13

Organized by county

Hudson County

■ Golden Door Charter School

Dates: 3/16/2020-3/27/2020

Reason: Precautionary cleaning

Hudson County

■ Learning Community Charter

Dates: 3/16/2020-3/27/2020

Reason: Precautionary cleaning

Hudson County

■ METS Charter School

Dates: 3/16/2020-3/27-2020

Reason: Precautionary cleaning

Hudson County

■ METS Charter School

Dates: 3/16/2020-3/27-2020

Reason: Precautionary cleaning

Hudson County

■ Secaucus

Dates: 3/16/2020-3/20/2020

Reason: Precautionary cleaning

Morris County

■ Butler

Dates: 3/13 - 3/27/2020

Reason: Concern about potential exposure to COVID-19 in school community

Morris County

■ Chester

Dates: 3/16 - 4/3/2020

Reason: Concern about potential exposure to COVID-19 in school community

Morris County

■ East Hanover

Dates: 3/13 - 3/27/2020

Reason: Concern about potential exposure to COVID-19 in school community

Morris County

■ Florham Park

Dates: 3/13 - 3/27/2020

Reason: Concern about potential exposure to COVID-19 in school community

Morris County

■ Hanover Township

Dates: 3/13 - 3/27/2020

Reason: Concern about potential exposure to COVID-19 in school community

Morris County

■ Harding

Dates: 3/16 - 3/27/2020

Reason: Concern about potential exposure to COVID-19 in school community

Morris County

■ Kinnelon

Dates: 3/16 - 4/10/2020

Reason: Concern about potential exposure to COVID-19 in school community

Morris County

■ Long Hill

Dates: 3/16 - 4/10/2020

Reason: Concern about potential exposure to COVID-19 in school community

Morris County

■ Morris Hills

Dates: 3/16 - 3/27/2020

Reason: Concern about potential exposure to COVID-19 in school community

Morris County

■ Morris School District

Dates: 3/16 - 3/27/2020

Reason: Concern about potential exposure to COVID-19 in school community

Morris County

■ Rockaway Borough

Dates: 3/16 - 3/27/2020

Reason: Concern about potential exposure to COVID-19 in school community

Morris County

■ Rockaway Township

Dates: 3/16 - TBD

Reason: Concern about potential exposure to COVID-19 in school community

Morris County

■ Roxbury

Dates: 3/16 - 3/30/2020

Reason: Concern about potential exposure to COVID-19 in school community

Morris County

■ Unity Charter School

Dates: 3/16 - 3/20/2020

Reason: Concern about potential exposure to COVID-19 in school community

Morris County

■ Washington Township

Dates: 3/13 - TBD

Reason: Concern about potential exposure to COVID-19 in school community

Morris County

■ West Morris Regional

Dates: 3/16 - 4/3/2020

Reason: Concern about potential exposure to COVID-19 in school community

Somerset County

■ Bedminster

Dates: March 16, 2020-April 13, 2020

Reason: Precautionary cleaning

Somerset County

■ Bernards

Dates: March 16, 2020-March 30, 2020

Reason: Precautionary cleaning

Somerset County

■ Bound Brook

Dates: March 23, 2020-April 14, 2020

Reason: Precautionary cleaning

Somerset County

■ Branchburg

Dates: March 16, 2020-April 14, 2020

Reason: Professional Development/Staff Training

Somerset County

■ Bridgewater-Raritan

Dates: 3/16/20-3/30/20

Reason: Precautionary Cleaning

Somerset County

■ Central Jersey College Prep

Dates: 3/16/20-3/20/20

Reason: Precautionary cleaning

Somerset County

■ Franklin

Dates: 3/13/20 & 3/16/20-4/14/20

Reason: Professional Development/Staff Training

Somerset County

■ Green Brook

Dates: 3/16/20-4/13/20

Reason: Precautionary Cleaning

Somerset County

■ Hillsborough

Dates: 3/13/20 & 3/16/20-3/27/20

Reason: Professional Development/Staff Training

Somerset County

■ Manville

Dates: 3/16/20-3/27/20

Reason: Professional Development/Staff Training

Somerset County

■ Montgomery

Dates: 3/13/20-3/30/20

Reason: Professional Development/Staff Training

Somerset County

■ North Plainfield

Dates: 3/16/20-3/30/20

Reason: Precautionary Cleaning

Somerset County

■ Somerset Co VoTech

Dates: 3/18/20- 4/13/20

Reason: Precautionary cleaning

Somerset County

■ Somerset Co. ESC

Dates: 3/16-4/14/20

Reason: Precautionary Cleaning

Somerset County

■ Somerset Hills

Dates: 3/16/20-4/10/20

Reason: Precautionary cleaning

Somerset County

■ Somerville

Dates: 3/16/20-4/13/20

Reason: Professional Development/Staff Training

Somerset County

■ South Bound Brook

Dates: 3/23/20-4/14/20

Reason: Precautionary cleaning

Somerset County

■ Thomas Edison Energy Smart Charter

Dates: 3/16/20-3/27/20

Reason: Precautionary cleaning

Somerset County

■ Warren

Dates: 3/16/20-4/10/20

Reason: Precautionary cleaning

Somerset County

■ Watchung Borough

Dates: 3/16/20-4/10/20

Reason: Precautionary cleaning

Somerset County

■ Watchung Hills

Dates: 3/16/20-4/10/20

Reason: Precautionary cleaning

Bergen County

■ Entire county (75 districts)

Dates: 3/16/20-3/27/20

Reason: Concern about potential exposure to COVID-19 in school community

Hudson County

■ Bayonne

Dates: 3/13/2020 - 3/30/2020

Reason: Concern about potential exposure to COVID-19 in school community

Hudson County

■ Elysian Charter School

Dates: 3/16/2020-3/27/2020

Reason: Precautionary cleaning

Hudson County

■ Guttenberg

Dates: 3/16/2020 - 3/2-/2020

Reason: Concern about potential exposure to COVID-19 in school community

Hudson County

■ Hoboken

Dates: 3/16/2020-3/27/2020

Reason: Precautionary cleaning

Hudson County

■ Hoboken Charter School

Dates: 3/16/2020-3/27/2020

Reason: Precautionary cleaning

Hudson County

■ Hoboken Dual Language Charter School

Dates: 3/16/2020-3/27/2020

Reason: Precautionary cleaning

Hudson County

■ Jersey City

Dates: 3/16/2020-3/20/2020

Reason: Concern about potential exposure to COVID-19 in school community

Hudson County

■ Jersey City Community Charter School

Dates: 3/16/2020-3/20/2020

Reason: Precautionary cleaning

Hudson County

■ North Bergen

Dates: 3/16/2020-3/20/2020

Reason: Concern about potential exposure to COVID-19 in school community

Hudson County

■ University Academy Charter School

Dates: 3/13/2020-3/27/2020

Reason: Confirmed exposure to COVID-19 in school community

Hudson County

■ Weehawken

Dates: 3/16/2020-3/20-2020

Reason: Precautionary cleaning

Middlesex County

■ South Brunswick

Dates: 3/11/2020-3/13/2020

Reason: Concern about potential exposure to COVID-19 in school community

Passaic County

■ Pompton Lakes

Dates: 3/12/2020 and 3/16/2020

Reason: Professional Development/Staff Training

Sussex County

■ Andover Regional School District

Dates: 3/13/20 and 3/16/20

Reason: Professional Development/Staff Training

Sussex County

■ Green Township School District

Dates: 3/13/20 & 3/16/20

Reason: Professional Development/Staff Training

Sussex County

■ Lenape Valley Regional High School

Dates: 3/13/20 & 3/16/20

Reason: Professional Development/Staff Training

Union County

■ Union County Ed Services Commission

Dates: 3/10/20 through 3/24/20

Reason: Confirmed exposure to COVID-19 in school community