The blaze broke out just after 2:00 a.m. Wednesday in the 4900 block of Brown Street in Philadelphia's Parkside section.
Officials suspect the elderly victim's living conditions may have caused him to become trapped inside.
Family members have identified the victim as Ezekiel Humphreys. He was well known, and well liked in the community.
Neighbor Steve Howard described Humphreys by saying, "He was a good man - helluva man. And I tried to get in to help but just couldn't get there."
Howard heard his elderly next door neighbor shouting as he was trapped on the second floor of his burning home. Howard tried to get in through the porch roof, but the smoke and flames were just too heavy.
Howard went on to explain, "My brother cut his hand a little bit when he broke the glass to try and get in through the glass - I tried to go in through the top, he tried to get in through the bottom. Smoke backed me off, so I couldn't even get to him."
Fire crews were called just after 2:15 a.m. and when they arrived, firefighters found fierce flames on the first floor that had burned through the stairwell.
Officials say there was an issue with hoarding in the home - items like books, bicycles, and boxes of electronics that fed the flames.
Philadelphia Fire Commissioner Lloyd Ayers says, "[The fire] was fueled by so much... combustibles inside of the room. We went through each and every room in the house and it's the same situation."
Fire investigators say there were no working smoke detectors inside the home.
This fatal fire happened on the same day a new city law goes into effect, requiring smoke detectors in one and two family buildings to have 10-year, non-removable batteries. The fire commissioner says they're working with other city agencies and community groups to increase services to the elderly.
"Last year, more than half of our deaths were citizens that were 50 and above. Many with some disabilities and some issues. We have to take care of this problem," said Ayers.
Humphreys lived in his home for decades. He was known as a great neighbor, an active neighbor and would often be seen on the block.
"He's 90 years old and in better shape than probably all four of us combined standing here," said Howard.
Another neighbor tells us, "He used to take an hour walk. Walk an hour one way, then walk back to the house. So, it was like a two hour walk."
Several neighboring homes were damaged by the fire. The Red Cross is assisting two families - eight people in all.
The investigation continues in what may have caused the blaze.