Philadelphia officials are offering a $20,000 reward for information about two men, including one charged in multiple homicides, who escaped a correctional facility and weren't discovered missing until nearly a full day after they slipped through a hole in a fence.

"We are adamant and working tirelessly to get these two dangerous individuals back in custody and that is the focus of our investigation," Blanche Carney, the Department of Prisons commissioner, said during a news conference Monday.

The manhunt comes in the wake of other recent jail breaches, including four men who escaped a detention center in Hinds County, Mississippi, in April. All four have since been apprehended or found dead, officials said.

The Philadelphia escapees were identified as Nasir Grant, 24, and Ameen Hurst, 18. They escaped the Philadelphia Industrial Correctional Facility through a hole in a recreation yard fence around 8:30 p.m. Sunday, Carney said.

They were discovered missing around 3 p.m. Monday, she said, noting there were three headcounts in the interim -- 11 p.m. Sunday and 3 a.m. and 7 a.m. Monday -- during which their absence wasn't noticed.

Officials are trying to figure out why those three counts didn't discover the two missing men, Carney said.

"Clearly the system screwed up and people didn't do what they were supposed to do," Philadelphia Mayor Jim Kenney said during the news conference.

Carney said Tuesday that she does not plan to resign and that lack of staffing is "not necessarily" what contributed to the escape.

"We are digging and combing through the timeline. It is imperative that we go through the timeline moment by moment so we can ascertain and ask those questions," Carney said.

The commissioner said that "a lot of rebuilding" of trust needs to happen in the community because "people are relying on us to provide public safety."

"We have victims' families here and my heart goes out to them," she said. "I'm accountable, because when I hold myself accountable, it's looking at, was policy followed? And if it wasn't then I have to take appropriate action."

The Philadelphia District Attorney's Office said Tuesday it's in touch with families and witnesses impacted by the homicides allegedly committed by one of the two prison escapees.

"The safety of victims and witnesses who may be at risk of intimidation or retaliation is of the highest importance to our prosecutors and to the DA's Victim Support Services Division," it added.

"The DA's Office is also in constant communication with Philadelphia Police and other law enforcement partners that are working with urgency to locate these fugitives, return them to state custody, and thoroughly investigate the incidents leading up to and immediately following the breach that occurred at the Philadelphia Industrial Correctional Center on Sunday."

David Robinson, president of a local labor union that includes corrections workers, said it was a "shame" that Carney has no plans to resign.

"It's time for new leadership. We had a vote of no confidence on May 2nd. It was unanimous," Robinson said.

Robinson said the city's prisons are "severely understaffed" and estimated that there was a shortage of almost 900 correctional staff across three facilities in Philadelphia, including around 100 at the prison where the escape happened.

"It's been that way for a while now. The critical understaffing started in 2019 and it just went totally down," Robinson said. "You can't cut corners inside a prison. You can't. One thing is for sure -- you cannot cut corners, you cannot cut posts."

Hurst is described as 6-foot tall and weighing 140 pounds. He has been in custody since March 21, 2021, and was being held on charges related to four homicides dating back to Christmas Eve 2020, Philadelphia Police Department Deputy Commissioner of Investigations Frank Vanore said at the news conference.

Grant had been in custody since September 28, and was facing gun and narcotics charges, Vanore said. He is described as being 5-foot-9 and weighing 160 pounds.

Investigators asked anyone with information to call 215-686-TIPS (8477) or 911.

As soon as the escape was discovered, Carney put the facility on lockdown and increased headcounts and perimeter patrols, she said. The Pennsylvania Department of Corrections was also asked to conduct a facility vulnerability assessment and security assessment, Carney said.

"I'm really angry about it," Kenney, the mayor, said. His top priority is finding Hurst and Grant, he said, and the second priority is assessing the system.

"There's no reason for this. And if everybody followed through and did what they were supposed to do, we wouldn't have this problem. So we're going to find out what happened, who didn't do what and get to the bottom of it," Kenney said.

The facility has protocols in place that weren't followed, Carney said, without providing details.

"That will be part of our investigation," Carney said. "The goal here now is to make sure that these two individuals are apprehended promptly."

An investigative team with the Philadelphia Department of Prisons is reviewing all security tapes and staff assignments before and after the escape, according to a news release from city officials.

Phone calls made by the men before their escape are also being reviewed.

The lockdown at the facility will continue through Friday, the mayor's office said.