A prisoner at a Philadelphia jail was repeatedly stabbed in an attack by three men on a cellblock with no guard nearby, leaving him to stagger back into his cell as no one came to his aid. The Sept. 30 incident, captured on surveillance video obtained by The Inquirer, went undetected after other prisoners rushed over to mop up the blood.

Corrections officers and prisoners said the situation was a consequence of intensifying staff shortages at the Philadelphia Department of Prisons, where violence has been simmering among men who spend 21 hours a day locked in their cells.

An Inquirer analysis of a week’s worth of recent staffing rosters revealed that 20% to 30% of shifts on a given day were filled by officers and supervisors working overtime. Many officers put in 16-hour or even 22-hour workdays.

“A lot of times officers are just being forced to stay there because there is no relief,” said a worker who spoke on condition of anonymity because staff are not permitted to speak with the media. “That’s why a lot of people are resigning. They’re tired of it.”

At the same time, more than 40% of shifts listed on the rosters were not filled at all.

Shifts often left unfilled included law library, recreation and education posts. Many cellblocks were listed as having one correctional officer to staff the unit — but no rover for backup or escort to move detainees. On many days, there was no one to administer disciplinary hearings or to process grievances.

» READ MORE: Video shows staff assaulting two men in Philly jails, where 14 have died this year

The department, according to the City Controller’s Office, is 537 officers short of its necessary staffing level, reflecting a 28% vacancy rate. Another 60 to 75 officers each day were listed as “injured on duty,” further limiting the pool of available workers. About 20 to 30 were listed “absent without leave.”

Philadelphia Prisons Commissioner Blanche Carney declined an interview request and a spokesperson said that for security reasons the city would not validate any internal information regarding staffing.

However, Carney said, any coverage of the department should take into account that American workers are leaving their jobs in record numbers — and prisons across the country are being hit especially hard. “Nationally, other jurisdictions are faced with some of the same challenges. We’re faring far better than other jurisdictions,” she said. That’s led to rising violence in facilities like New York’s Riker’s Island, where staff have reportedly ceded cellblocks to gang control.

In the Pennsylvania Department of Corrections, on the other hand, the correctional officer and trainee vacancy rate is just 5.6%, spokesperson Maria Bivens said. She described that as sufficient to maintain security, but said recruiting is ongoing.

In Philadelphia, the consequences of the shortage have been especially grave: At least 21 people have died in jail during the pandemic, including five by homicide and four by suicide. Staff say riots and unrest have grown more frequent.

The man injured in the Sept. 30 assault, at Curran-Fromhold Correctional Facility, was later treated for his injuries, according to a person familiar with the situation. A city spokesperson said the prison could not confirm the incident, but added that all reported incidents of violence are investigated.

In another recent incident, men on two cellblocks at Riverside Correctional Facility refused to go back in their cells, complaining of lack of access to phones and excessive time locked in, according to an Oct. 25 report obtained by The Inquirer. A city spokesperson said the incident was resolved peacefully within 20 minutes, and said detainees there receive at least three hours a day out of their cells as mandated by a federal court order.

» READ MORE: 'Unit unsafe': Inside a week of riots, fires and destruction at Philadelphia jails

Yet, one prison worker said the conditions on cellblocks where riots occurred are alarming: “The guys are not getting access to anything they should get access to. They haven’t showered in weeks. They haven’t gotten phone calls in weeks. They haven’t been let out of the cells due to the lack of correctional officers. They’re not getting commissary, so they can’t purchase envelopes to send mail, even. They basically have no contact with the outside world.”

Susan Elliott, whose son Joshua is on one of those cellblocks, said when he was finally allowed to call home he described going three weeks without a shower and three days without food. He told her that after the riot he was “beaten in the genitals” and pepper sprayed five times. With no access to a shower, he had to put his face in the toilet to rinse off the chemicals, she said.

Two jail workers said staff are struggling to maintain operations like meal service, at times delivering breakfast and lunch trays together. They also said sliding doors along corridors have at times been left open because there is no one to monitor them. Prison and union representatives denied that.

A second video obtained by The Inquirer from August, however, appears to show such a scene: A detainee wanders into an area where other incarcerated men are working unsupervised, loading food onto carts. He tries to steal some food, gets into an argument, and is stabbed, before others break up the fight and shoo him away. No officer shows up to intervene.

A class-action lawsuit over the jails’ pandemic response was amended in October to allege that the department is not fulfilling its basic obligations, such as responding to medical emergencies.

“We’ve now been getting very serious reports about delays in medical care, increased violence and not being able to get to court,” said Su Ming Yeh, executive director of the Pennsylvania Institutional Law Project.

A federal judge overseeing that lawsuit previously ordered the jails to restore programming, family visits, and full law library access by Oct. 25. According to the amended lawsuit, none of those services is yet available.

The department recently hired 30 new officers and pitched staff on a new action plan: a 12-hour workday. The city says that plan will “increase coverage across all shifts, while also increasing days off for staff members.”

David Robinson, president of the correctional officers’ union, Local 159 of AFSCME District Council 33, was doubtful. He said some officers have warned they’ll quit if that schedule takes effect.

“Now we’re in a situation where we don’t have staff. That makes the prisons dangerous,” he said. “They had an obligation to keep these jails safe. And I’m going to be honest: I believe they failed.”