They were strangers when their lives converged at the white-painted brick rowhouse in the middle of Kennedy Street in Northwest Washington.

Born in Ethi­o­pia, they had come to the United States over the years to seek work and send money to their families. A home health aide. A warehouse box stocker. A retiree. And a woman they call “Mama” who speaks only a few words of English and relies on the others for assistance.

One by one, they found their way to 708 Kennedy St. NW, joining other tenants from Ethi­o­pia in a rowhouse the city said lacked rental permits, and living in rooms occupants described as not much larger than a queen-size mattress.

A fire Sunday morning that started in the basement killed a man from Ethi­o­pia who lived there and left a 9-year-old boy with grave injuries. A cause had not been determined, but D.C. fire and regulatory officials said the narrow corridors, complex layout, smoke detectors that didn’t work and metal bars covering the windows and front door combined for deadly results.

Dual investigations are underway into the fire and the living conditions, which authorities said could lead to a criminal inquiry by police depending on what is uncovered. The names of the boy, whose limp body was carried out in the arms of a firefighter, and the man, who died at a hospital later Sunday, had not been made public.

“I thought, ‘If I stay in my room, I die,’ ” said Sara Mengiste, 46, who was alone on the second floor when she smelled something burning about 9:40 a.m. Blinded and choking on thick smoke, she made it downstairs by feel and with the help of police officers who, along with bystanders, ripped the metal bars off the front door as people inside screamed for help.

Guided by the shouts from Officers Stephen Benson and Victoria Freeman, who could not get beyond the entrance to the home because of the smoke, Mengiste stumbled outside, her legs bruised from a fall and her airways charred. She was briefly hospitalized. Firefighters found the man and boy on the first floor.

Property records and regulatory authorities identified the owner of the property as James G. Walker. He has at least two other residences in that name, one in West Baltimore, the other on Whittier Place, a block from Rock Creek Park in Northwest Washington. That appears to be where he lives.

Repeated attempts over two days to reach Walker were unsuccessful. He did not return messages left at one phone number linked to him, and other numbers were disconnected. No one was at the house on Whittier Place on Tuesday. The blinds were drawn and there was a “No Trespassing” sign in the window.

On Monday, Mengiste gathered with her three top-floor neighbors, who were at church when the fire broke out. They are now sharing a single motel room with two beds, paid for by the Red Cross, worried about clothes, documents and finding a permanent place to live. The women said that the room is paid for until Sept. 3 and that they don’t know what will happen after that.

“We have nothing,” said Mengiste, who was anxious to return to her warehouse job, fearing she might be fired and not wanting to miss sending money to her mother and relatives in Ethi­o­pia. “I have no choice,” she said. “I don’t go out to enjoy. I have to help my family. I go to work. I come home. I go. I come. That’s my life. I’m the one person. I take care of everybody.”

Now, Mengiste fears, “We will be homeless.”

The fire exposed a hidden problem of clandestine rental houses whose owners can avoid scrutiny while attracting tenants who are poor or immigrants unsure of their rights, or unable to find safer options. The four women said they had no idea their residence was not permitted, and District officials said it was not inspected because no complaints were filed. They had no reason to suspect people were living there.

“Anybody can choose to operate a rental business in the shadows,” said Ernest Chrappah, director of the D.C. Department of Consumer and Regulatory Affairs. “That’s just a reality.”

While Chrappah said unpermitted rentals represent a “tiny fraction” of the 180,000 rental properties his agency oversees in the District, he noted the impact of even a few “can be devastating, as we see here. This is a wake-up call, not only to landlords, but to tenants.”

Chrappah said the Kennedy Street rowhouse “was an unlicensed rental” that had 12 people living there. He stressed that tenants can file complaints anonymously and that “no matter your status, you can get help from us to ensure that basic life safety protections are present.”

On the outside, the nondescript rowhouse appeared to be just another storefront blending in with a tax service, a day-care center, a dance studio and a taco eatery lining the Kennedy Street commercial strip in Brightwood Park. District records show the rowhouse is listed as the address for Flowers Medical Care LLC. A sign above the burned house says “Walker Pharmacy” with a telephone number that is disconnected. Jonathan Kuhl, a spokesman for the DCRA, said the rowhouse has a home occupation permit for a “mail-order business.” He said there is no license for a rental property or a certificate of occupancy.

The four women who lived on the top floor — Mengiste; Fanaye Getaneh, the oldest in the group; Selamawit Yehualashet, 41, the home health aide; and Zewdmesh Bantle, 66, who is retired — said the house held no pharmacy, but was carved into a dozen separate, tiny living quarters with communal bathrooms and kitchens.

The three younger woman said that Walker was their landlord and that they had two-year leases. They said their monthly rents ranged from $300 to $550. Mengiste said they paid their rent in cash to Walker.

The tenants described crowded living conditions in which they could barely move off their beds and stand. The corridors were so narrow, they said, that opening one door would sometimes block another from opening. They said the top floor and basement, where the man and boy lived, each had one shared bathroom and kitchen. The first floor had neither.

Both the DCRA and the fire department are conducting investigations in the wake of the Kennedy Street fire.

Many, if not all, of the tenants were from Ethi­o­pia, and they often congregated across the street at Selassie Ethio­pian Market, where they joined the owner, Solomon Teferra, for midmorning coffee and chats about the home country. He supplied them with bread and spices.

Several of the tenants attended Debre Selam Kidist Mariam Ethio­pian Orthodox Church on Buchanan Street. The man killed in the fire did odd jobs there, they said.

Mengiste came to the United States a little less than five years ago on a dangerous route through Sudan and said she found the Kennedy Street apartment through an ad in a newspaper targeting the District’s Ethio­pian community. Getaneh has lived here 19 years, the past seven on Kennedy Street. Bantle is a U.S. citizen who has lived here 28 years and receives Social Security benefits that she said, after paying rent, leaves her little left.

At the motel, they pointed to their mattresses to show the approximate size of the rooms they rented.

Said Mengiste: “You see this room, you are going to say, ‘How do these people live?” ’

Jennifer Jenkins contributed to this report.