This, as the total number of coronavirus cases in Pennsylvania topped 4,000.
Wolf extended the stay at home order to several additional counties, mostly in central Pennsylvania. The order was already in effect for Philadelphia and the surrounding counties.
The stay at home order has been extended until April 30, Wolf said, which is "in line with what is being done on the national level."
Wolf said there is no date for when schools and businesses could reopen.
"We're going to keep our schools and businesses closed as long as we need to keep them closed to keep Pennsylvania safe. Right now, it isn't safe," he said.
On Tuesday, following the governor's orders, the School District of Philadelphia announced in a letter the indefinite closure of its schools.
until further notice.
"Safeguarding the health and well-being of our students, our staff and the broader Philadelphia community is our highest priority. We will continue to work closely with the Pennsylvania Department of Education, the Philadelphia Department of Public Health and other agencies to determine when it will be safe to reopen our schools," the letter read.
Under Wolf's order, people in the 26 affected counties may leave their homes to work at a business that's still open, go to the grocery store or pharmacy, visit a doctor, care for a relative, get outside to exercise or for several other reasons.
As of noon Monday, there were 4,087 COVID-19 cases in Pennsylvania with 48 deaths.
For a complete breakdown of the age ranges and home counties of each positive COVID-19 patient provided by the Pennsylvania Department of Health, click here.
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Gov. Tom Wolf announced Monday that all schools will remain closed indefinitely as Pennsylvania reported nearly 700 new cases of the coronavirus.
Wolf also extended his order to stay at home to more counties - Carbon, Cumberland, Dauphin and Schuylkill - and said the social distancing guidelines will be extended until April 30.
President Donald Trump declared that a major disaster exists in the Commonwealth of Pennsylvania and ordered Federal assistance to supplement the Commonwealth and local recovery efforts in the areas affected by the coronavirus pandemic.
The President's action makes Federal funding available to Commonwealth and eligible local governments and certain private nonprofit organizations for emergency protective measures, including direct Federal assistance, for all areas in the Commonwealth of Pennsylvania impacted by COVID-19.
COVID-19 cases reported by the state Health Department on Monday rose by 693 to nearly 4,100. There were 10 new deaths, bringing Pennsylvania's total to 48. The agency initially reported 11 new deaths Monday but later revised the number.
Officials said those diagnosed are hospitalized or in isolation.
For most people, the coronavirus causes mild or moderate symptoms that clear up in a couple of weeks. Older adults and people with existing health problems are at higher risk of more severe illness, including pneumonia, or death.
The Department of Corrections said inmates throughout the state prison system will largely be confined to their cells to keep the virus from spreading after an inmate at State Correctional Institution at Phoenix in Montgomery County tested positive for COVID-19.
"Quarantining the entire system is in the best interest of our employees and our inmates," Corrections Secretary John Wetzel said in a news release.
Inmates will only be allowed out of their cells for video visits, phone calls and access to the law library.
The Corrections Department incarcerates nearly 44,600 inmates in 25 state prisons.
Meanwhile, the state Supreme Court was asked Monday to order the release of some inmates from county jails to help reduce the virus's spread. The county jail system isn't impacted by the Department of Corrections quarantine.
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ACLU SUES TO REDUCE JAIL POPULATION
A petition filed with the state's high court by the American Civil Liberties Union of Pennsylvania said tight inmate quarters, a lack of sanitation, and a limited ability to treat and quarantine people suspected of having COVID-19 presents an "extraordinary public health risk" to inmates, staff and surrounding communities.
Once the virus enters a jail, it's "virtually certain to spread like wildfire," the petition said.
The Supreme Court was asked to order the release of inmates at high risk of serious illness from COVID-19, and those nearing the end of their sentences, eligible for work release or held on cash bail before trial.
The plaintiffs are the Pennsylvania Prison Society, an advocacy group, along with five inmates.
Other states, including New Jersey, have taken steps to reduce their jail populations, as have Allegheny, Lackawanna and Lancaster counties in Pennsylvania.
The legal action was taken as Pike County officials announced Sunday that a staffer at the jail tested positive for COVID-19. Inmates who had direct contact are under quarantine.
BANKS ASKED TO PROVIDE RELIEF
The Pennsylvania attorney general's office is seeking banks and financial institutions to join a new program that expands consumer protections under a recently passed federal law.
Under the program, dubbed PA CARE Package, lending institutions will make loans more easily available to small- and medium-sized businesses and will provide a 90-day grace period for mortgages; auto and other consumer loans; and late and overdraft fees and similar charges.
Participating banks must also agree to a minimum two-month moratorium on foreclosures, evictions and vehicle repossessions, and promise not to negatively impact the credit of people who get relief from consumer loans.
The attorney general's office said PNC Bank was the first to agree to participate.
UNEMPLOYMENT SURGES AGAIN
Pennsylvania set another record for filings for unemployment compensation benefits last week with 405,000 filings in the seven days through Saturday, as businesses shut down and laid off workers.
That beat the record set a week earlier at 379,000, which itself was highest in the nation.
Unemployment filings surged after Wolf first asked and later mandated that nonessential businesses close their physical locations.
The emergency relief bill signed last week by President Donald Trump adds 13 weeks of benefits - from 26 to 39 in Pennsylvania - plus $600 a week in benefits. It also expands eligibility to workers who don't pay into the system and normally aren't eligible, but who lost jobs due to the pandemic.
The Associated Press contributed to this report.