The logbook entries from J Unit — a disciplinary custody unit at Philadelphia Industrial Correctional Center — are terse, often just a few words.

But this week, logs obtained by The Inquirer told a story of mounting alarm.

On Monday at 8:35 a.m., an officer at the jail noted that cleaning was underway — adding, in parentheses, “flood.” By 9:10, a prisoner had “kick[ed] out the receiving room door.” More entries noted that cell windows were broken, and a stretcher was called for a slip-and-fall in the floodwater.

By that evening, prisoners were “consistently breaking/shattering cell door windows on both tiers.” And, as of Tuesday morning, staff had given up touring the unit altogether.

“Unit unsafe,” an officer wrote, adding that prisoners were armed with sticks and were throwing feces and that there was just one officer on a four-man post.

All that, it turned out, was only the run-up to what union officials termed a riot at PICC on Wednesday night. Almost 90 incarcerated men broke out of their cells, took over a housing unit, and barricaded the entrance, they said.

Staff said it’s the latest in a series of disturbances at Philadelphia jails this year — and a manifestation of an ongoing crisis exacerbated by insufficient staffing and inadequate locks.

“We’ve been screaming for help for a long time,” said David Robinson, president of Local 159 of AFSCME District Council 33, which represents correctional officers. Union leadership is set to meet with city officials and Prisons Commissioner Blanche Carney this week to discuss the PICC situation.

A spokesperson for Mayor Jim Kenney said both Wednesday incidents were quelled within two hours. Three incarcerated men were treated at area hospitals “as a result of the force necessary to quell the incident” but were released back to the prison, acting communications director Kevin Lessard said. He added that he could not release more details because the incident is still under investigation.

According to union officials and staff on the scene, the lone officer on the unit fled to avoid the potential risk of a hostage situation. They said it took an emergency response team of about 60 officers several hours — and the use of bolt-cutters, sledgehammers, and flash-bang grenades — to regain control of the area.

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

Despite the melee, no formal incident report had been circulated as of Thursday morning, according to a correctional staff member who declined to be named because staff are not authorized to speak with the media. A city spokesperson said all appropriate reports had been generated and a full investigation was underway.

“It was brewing for a couple days and they were trying to keep it hush-hush,” the officer said, adding that people incarcerated there had tossed toilet paper “firebombs” and set several mattresses ablaze.

“They wreaked havoc, destroyed city property, damaged and vandalized plumbing systems and surveillance cameras,” said Eric Hill, business agent for the union. The two units have been emptied and require extensive repair and cleaning, he said.

Mass disturbances at the jails were highly unusual in the past but have repeatedly occurred this year at PICC and at Riverside Correctional Facility, another men’s jail in the same Philadelphia Department of Prisons complex in Northeast Philadelphia.

The crisis has escalated as incarcerated people have learned to hack the locks. As one man imprisoned there, Michael Flynn, explained in a letter to The Inquirer, “simply using a small piece of toilet paper or small pieces of playing cards,” can prevent the lock from fully engaging. “Then all you need is a small piece of plastic to slide it open. ... Inmates were allowed to run into other inmates’ cells to steal commissary and/or to assault each other. One was severely stabbed while he slept.”

In response, staff added sliding bolts — but this week incarcerated men evaded that layer of security by smashing the windows in their cell doors and reaching through to unlatch them.

A recently retired supervisor who helped quell a similar incident at Riverside in May said it took six hours to regain control after men broke the lids off plastic storage boxes and fashioned them into swords. “These guys were armed and ready,” he said. “They had their faces covered.”

This year, 14 people have died in the Philadelphia jails, a death rate far above the national average. The facilities have been operating under orders by a federal judge, in partial settlement of a civil rights lawsuit filed over the pandemic response. A Philadelphia investigating grand jury has subpoenaed documents related to a similar jail uprising that occurred at PICC in August.

» READ MORE: Philly prison ‘crisis’ now includes a grand jury investigation and more court-ordered reforms

Philadelphia City Controller Rebecca Rhynhart in June said the city must urgently address the jails’ staffing shortage, then 382 officers short of a full complement. Now, that shortage has grown to 520 officers, according to the controller.

The staffer who was part of the Wednesday night response at PICC said some newer officers were shaken. “[They] said, ‘I don’t know if I’m coming back to work. I’m seeing this daily. I didn’t sign up for this,’” the staffer said. “They’re calling out sick, saying, ‘I don’t feel safe.’”

Claire Shubik-Richards, who heads the Pennsylvania Prison Society, called this week’s incidents predictable and preventable. “Everyone in city and state government has been on notice for months that conditions at the Philadelphia prison are dangerous and not in control,” she said.

She said a crisis manager should be appointed to coordinate a response across branches of government in order to reduce the population, expedite court cases, and stabilize staffing.

“It’s not going to stop,” Shubik-Richards said, “until the city starts dealing with this like the crisis it is.”