As flames devoured the North Philadelphia rowhouse beneath her last week, Alita Johnson cowered in a small third-floor bathroom with her father and 3-year-old son, pleading with 911 to send someone to their rescue.

Firefighters responded. They extinguished the blaze and rescued other tenants. But when they cleared the scene and packed up to leave, Johnson and her family remained behind – missed and overlooked.

It wasn't until 72 hours later that their bodies were discovered – and only then after relatives say they made repeated calls to officials to report that the Johnsons still were missing.

As those family members continued to demand answers Tuesday, Fire Commissioner Adam Thiel offered a heartfelt apology and said that his department would continue to investigate what went wrong.

"While we can never share the family's pain, this is extremely upsetting to us," he said at a news conference at Fire Department headquarters at 240 Spring Garden St. "Every fire death is tragic. … The circumstances here make this even worse."

In an update on the ongoing probe, Thiel confirmed for the first time that investigators believe it was Alita Johnson who first reported the blaze at what city officials have described as an illegal boarding house at 1855 N. 21st St., and that she had remained on the phone with dispatchers for nearly 10 minutes before her death.

He said investigators still were sorting out how firefighters could have missed that Johnson, her 64-year-old father, Horace, and her son, Hashim, had not been rescued or accounted for before they left the scene early last Wednesday.

But even as Thiel and other city officials expressed their condolences and confusion on Tuesday, they also sought to blame the property's owner for unsafe conditions that may have contributed to last week's tragedy.

Brian Abernathy, first deputy managing director, told reporters that he planned to meet with the District Attorney's Office in the coming days to discuss potential criminal charges against the building's management company, Granite Hill Properties, and the business' owner, Tyrone Duren.

Although investigators believe that as many as 10 people resided in the house at the time, the building did not have an active rental license and was not zoned to be a multifamily dwelling.

In fact, said David Perri, commissioner of the Department of Licenses and Inspections, his office previously had sued Granite Hill for running an unlicensed boarding house in 2014 — a case that was resolved with Duren's pledging he would vacate the building. Sometime between then and last week, Granite Hill began renting the property again.

"Boarding houses, especially those that are not run very well, provide a heightened safety concern because [tenants] add microwaves, they add hot plates and things that can overload the electrical circuits," Perri said.

Neither Duren, a 47-year-old former agent with the U.S. Department of Homeland Security, nor his lawyer, John Kirby, returned calls for comment Tuesday.

However, court records show that Granite Hill and its owner have a lengthy history of run-ins with the law.

Granite Hill has been sued more than 20 times for various code violations or unpaid tax bills on the more than 30 properties it manages in largely low-income neighborhoods across the city.

Duren himself faces federal charges in California, accused of stealing money from drug dealers while working for DHS – money that prosecutors say he laundered through his Philadelphia property holdings and used to purchase some of the properties Granite Hill continues to rent to tenants in the city, including the one in which the Johnson family was living.

Perri said Tuesday that his office had launched a full inspection of all properties owned by Duren and Granite Hill in response to the fire.

The cause of the blaze, which began on the second floor, remains under investigation.

Thiel described a chaotic scene when firefighters arrived at the property. Two residents managed to escape on their own. The body of a third tenant, who apparently died in a jump from a window, was found outside. His name has not been released.

As responders ascended a staircase to the third floor, where the bodies of the Johnson family later would be found, the floor collapsed beneath them, sending firefighters plummeting to the ground floor and causing injuries that sent two to the hospital.

Fire officials later were able to drag a ladder inside the building to search as much of the third floor as they could. But at the time, they found no one in the areas to which they could reach, Thiel said.

When investigators asked one of the tenants who had escaped whether anyone was still in the building, Thiel said, they were told no.

Quoting one of the occupants who made it outside, the fire commissioner said that his responders were told: "The last time I [saw] those people was a month ago. They moved out, and I haven't seen those people in a little while."

But all that came as little comfort Tuesday to the Johnsons' relatives, who are left to plan their funerals, with services scheduled for Friday at Pathway Evangelistic Church in Frankford.

Fire Commissioner Adam Thiel speaks during a news conference about a fatal fire on North 21st Street at the Philadelphia Fire Department administration building on Tuesday, March 27, 2018.Family members have said that it took them nearly three days to persuade the Fire Department to return to the scene to search for their missing relatives.

Thiel said Tuesday that his department's records revealed no trace of such a phone call until the one Friday that prompted investigators to return to the site and discover the Johnsons' bodies.

Still, as he met with the family Tuesday, he said, he offered his condolences and shared in their heartbreak and frustration.

"Despite giving it our best, we couldn't save these folks," he told reporters afterward. "We know we can't save everybody, but I promise you, we tried."