How did two prisoners escape from a Philly jail? As the search continues, an investigation is looking for answers.

»Update: Nasir Grant was arrested Thursday night, authorities say

The two men were not cellmates, nor do authorities believe they had a friendship that predated the last few months inside a Philadelphia jail.

But Sunday night, Nasir Grant, 24, who is awaiting trial on gun and drug charges, and Ameen Hurst, 18, who is accused of killing four people, shooting two more, and committing two robberies — both managed to walk out of “H” Unit at the Philadelphia Industrial Correctional Center, officials said.

There, the men sneaked through a triangle-shaped hole in the fence, then climbed over two other fences topped with barbed wire — leaving behind blood and bloodied clothes, according to law enforcement sources briefed on the case who requested anonymity to discuss it.

Their disappearance — unprecedented in recent city history — went unnoticed by prison staff for nearly 19 hours. Part of that may have been due to staffing issues: One source close to the investigation said the “H” Unit on Sunday night had only one guard assigned to oversee more than 90 prisoners. And a union official said that, for long periods, the unit was not staffed at all.

On Tuesday, nearly two days after Grant and Hurst committed their breakout, a number of questions remain unanswered — including how they avoided detection while fleeing, when the hole in the fence was cut, and why their absence was not noticed during three separate body counts in the jails on Sunday and Monday.

The matter is now the subject of investigations by both the prison system and Philadelphia police. Grant and Hurst remained on the lam Tuesday, with the U.S. Marshals leading a search for them.

Prisons Commissioner Blanche Carney, speaking to reporters outside the jail Tuesday, said she could not offer many specifics about the situation due to the ongoing investigations.

“There are a lot of questions I know you want me to answer, but I’m not going to answer prematurely,” she said. “It is imperative that we go through the timeline moment by moment so we can ascertain and answer those questions.”

In an update released Tuesday evening, the city said that the Department of Prisons was investigating phone calls Grant and Hurst made before their escape, and that “staff and other inmates at the facility are being interviewed.” Jails are expected to remain on lockdown until Friday, the city said, “to facilitate a thorough review of the perimeter and security points.”

Capt. John Ryan of Northeast Detectives, who is overseeing the police investigation into the escape, said: “Clearly, procedures weren’t followed.” Still, he said the probe was in its early stages.

David Robinson, president of Local 159 of AFSCME District Council 33, which represents correctional officers, said the unit from which the two men escaped was effectively unstaffed on Sunday evening — the result of an ongoing staffing crisis in the city’s jails.

In addition, Robinson said two other critical posts — the armed perimeter patrol, and an armed post near State Road at the gate to the back road, known as Post 13 — had been unstaffed.

“These two vital posts were closed — and they have been closed for honestly almost a year,” Robinson said. “When you cut posts and you cut corners, this is where we’re at.”

Carney said it was “not true” that any section of the prison was completely unstaffed. But she said how and where employees were at the time of the escape was part of the prison’s investigation.

“For this event, we’re looking to see what that timeline and video review will tell us,” she said.

The jails have been subject to the oversight of a monitor appointed by a federal judge since last year, in response to a class-action lawsuit over conditions there. In addition, the city contracted former Pennsylvania Corrections Secretary John Wetzel to consult on the jails.

Carney on Monday said the city has also called in the Pennsylvania Department of Corrections, requesting an immediate security assessment of its facilities.

The union held a news conference outside PICC last week to announce a vote of no confidence in Carney’s leadership, citing more than 800 officer vacancies that have left the prisons short-staffed by about 40%. They described the jail’s conditions as both a public-safety and a human rights issue.

Staffing concerns lingered over another question about the escape: how and why the disappearance of two prisoners was not detected until Monday afternoon.

A preliminary incident report obtained by The Inquirer said prison staff was made aware of the escape only after other prisoners notified them about it Monday about 3 p.m.

John Mitchell, a spokesperson for the city’s prison system, said that was “patently false,” and the city later said the document was “forged.” Mitchell said corrections officers noticed that Grant and Hurst were missing after a mandatory body count about the same time that afternoon.

Still, neither Mitchell nor Carney could say why officers hadn’t noticed the missing prisoners in three other counts performed earlier Monday and on Sunday night. Carney said the investigation would seek to determine what “lapses” in protocol there may have been before and after the escape.

“If there are any deviations from [our policies], we have to do the investigation to see what didn’t happen,” she said.

In addition to investigating the escape, authorities on Tuesday continued searching for Grant and Hurst.

Before he broke free, Grant was jailed on gun and drug charges, accused of possessing cocaine, marijuana, and six handguns he was not allowed to have because of a previous felony conviction, according to court records.

Hurst, meanwhile, is accused of killing four people, and critically injuring two others, in three separate shootings in less than three months. Deputy Police Commissioner Frank Vanore on Monday described Hurst as “a very dangerous individual.”

The first shooting occurred on the morning of Christmas Eve in 2020. As 20-year-old Dyewou Nyshawn Scruggs was walking and filming himself on Instagram Live, police say, Hurst ran up and shot him multiple times, leaving even his phone riddled with bullets, his family said in an obituary.

When detectives watched surveillance footage of the shooting, court records say, one detective recognized the shooter as Hurst, a teen he’d previously arrested for gun-related crimes. Law enforcement had been monitoring Hurst’s social media for months, as he was a known affiliate of street groups in the West Philadelphia and Overbrook area, the records say.

Less than three months later, on March 11, 2021, police say, Hurst shot four men sitting in a car on the 1400 block of North 76th Street. Naquan Smith, 24, and Tamir Brown, 17 were killed, and two others were seriously wounded.

Police later recovered a recording they believe to be Hurst, admitting to the shooting. “Pick ya man Tamir up, bro,” Hurst said, according to court records. “I ate him up in that wheel.”

In addition, the records say, eight hours after the shooting, one of Hurst’s friends messaged him about the killings. Hurst allegedly replied: “I did it!!!”

Then, just one week later, police say, Hurst killed 20-year-old Rodney Hargrove near the front gates of the Curran-Fromhold Correctional Facility. Hargrove had been released from jail less than an hour earlier, and was waiting outside for relatives to pick him up when, police say, Hurst pulled up in a car and shot him multiple times.

Police say they believe it was a case of mistaken identity. In messages sent just hours after Hargrove was killed, records show, Hurst messaged a friend, appearing to admit that he’d been targeting a man named “Sid” but shot the wrong person.

The Hargrove family, in a statement through their lawyer, said they pray “that no one else is injured or further harmed” by Hurst, and hope that “he is apprehended quickly.”

Authorities ask that anyone with information call 911, the U.S. Marshals Service at (800) 336-0102, or Philadelphia Police at (215) 686-TIPS (8477). Officials were offering a reward of as much as $25,000 for the capture of each man.