More patients infected with the coronavirus were filling Philadelphia-area hospitals on Thursday, and some hospitals in the region were “at or near capacity, especially for intensive care unit beds,” city Health Commissioner Thomas Farley said.

In Philadelphia and its surrounding counties, 1,551 COVID-19 patients were hospitalized as of Thursday afternoon, the highest number to date, and hospital data indicated that “definitely we’re not past the worst of it,” Farley said. Hospitals were preparing to transfer patients to other hospitals upon running out of space, but Temple University’s Liacouras Center also stands ready to accept patients if needed, he said.

One model predicted that Thursday would be the state’s peak number of hospitalizations and that deaths would peak in several days, Pennsylvania Health Secretary Rachel Levine said, but she did not indicate whether that seemed to be occurring. “We will see if that model is true,” she said.

Still, Pennsylvania officials on Thursday were “very confident that we’ve flattened the curve,” Levine said, and have recorded a slowdown in the number of coronavirus cases, the percentage of tests that are positive, and reports from emergency rooms about virus diagnoses and flulike symptoms.

Pennsylvania reported a total of 707 deaths and 27,735 cases on Thursday. New figures released by the Department of Health after pressure from experts and the public showed that black Pennsylvanians make up a disproportionate share of coronavirus patients for which the state has race data — about one-third of the cases.

But the state’s testing ability has decreased amid a shortage of the chemicals needed for testing, Levine said, saying the state has recently had “great difficulty” ordering supplies.

In New Jersey, the growth rate in hospitalizations was flat, the state health commissioner said. But the number of people testing positive for the virus passed 75,000, and the death toll is now higher at 3,518 than the number of Garden State residents who were killed during World War I.

Amid a national argument about when the country may reopen, Gov. Phil Murphy extended New Jersey school closures to at least May 15, and New York’s stay-at-home order was extended until May 15. Pennsylvania Gov. Tom Wolf said he had not made plans to match New York’s extension but hoped to make a decision about relaxing social distancing measures — set to expire statewide April 30 — as soon as health officials deem it safe.

“We cannot be guided by emotion,” Murphy said. “We need to be guided by where the facts on the ground, science, and public health take us.”

President Donald Trump, who had been at odds with the governors, said in a Thursday evening briefing that “New Jersey’s been hit unbelievably hard” and doesn’t predict “they’re gonna be opening next week."

Announcing his guidelines for how the nation could return to normal life, Trump said “it’s going to be up to the governors” to make the decision on when to reopen their economies — a reversal from Monday, when he inaccurately said he had “total” authority to order reopenings.

He appointed Sen. Pat Toomey (R., Pa.) to the White House task force on reopening the economy. Meanwhile, Murphy named two officials from President Barack Obama’s administration to the multistate council convened by seven Northeastern governors to coordinate an eventual return to normal life.

Pennsylvania officials were in discussions about the path forward, and Wolf said he planned to make a decision about lifting shutdown measures, particularly in certain counties that have seen fewer cases, when it was safe. Schools in Pennsylvania are already closed for the rest of the academic year.

“I think Pennsylvanians need some certainty in terms of when we’re going to be able to start getting back to life as we once knew it,” he said.

The day after Pennsylvania Republicans passed a bill, which Wolf said he would veto, to reopen some businesses, the commonwealth’s top health official said letting the virus spread through the community — or creating so-called herd immunity, indirect protection from a disease that happens when large amounts of a population develop immunity — would have been “potentially catastrophic.”

The virus is 10 to 20 times more contagious than the flu, she said, and if it had spread unchecked, “then we wouldn’t have 27,000 cases, we’d have 70,000 cases,” and at least triple the number of deaths.

The Philadelphia health commissioner declined to elaborate on which hospitals — or how many — are nearing capacity, but said it is “a minority of hospitals in the city,” and there is still plenty of space available for additional patients.

After Philadelphia’s rate of infection began to slow in recent days, numbers may be plateauing but still have not begun a steady decrease, he said. An unusually high number of deaths and new cases — 42 and 604, respectively — were reported by the city Thursday because of a backlog in laboratory results, Farley said.

Two suburban health officials said many of their counties’ deaths have been in residents of long-term care facilities. About 65% of Montgomery County’s coronavirus deaths have been such patients and just under half of Bucks County’s.

“We’re not seeing a lot of cases outside the facilities anymore,” said Bucks County Health Director David Damsker. “Any surge [in hospital admissions] that will happen will be from long-term care patients.”

Montgomery County hospitals still have available beds and ventilators for patients, which County Commissioners Chair Val Arkoosh said was a “direct result” of residents’ willingness to stay home in recent weeks.

In northern New Jersey, at least 17 bodies were found piled in a long-term care facility whose owner said had gotten “overwhelmed” by COVID-19 deaths. Murphy directed New Jersey Attorney General Gurbir S. Grewal to investigate the facility and any other that reports a “disproportionate” number of deaths.

New Jersey will receive 100 ventilators from New York, in a show of partnership between the two hardest-hit states from the pandemic, Murphy said.

And he said rent increases on New Jersey Housing Authority properties — up to 36,000 rental units meant for low- and moderate-income state residents — will be suspended during the pandemic.

His school-closure order covers all public and private schools, colleges, and universities and told schools to continue educating students “through appropriate home instruction.”

The governor said that he has heard frequent pleas, particularly from parents of athletes and those about to graduate, to salvage part of the academic year, and that the May 15 date gives New Jersey “at least one more shot to reassess” the public health situation and possibly let students return to schools.

“Nothing would give me more joy than being able to say we’re ready to go, but we’re not there yet,” Murphy said.

Contributing to this article were staff writers Anna Orso, Erin McCarthy, Allison Steele, Kristen A. Graham, and Maddie Hanna and the Associated Press.