The victims were identified by family members as Rasheeda Wilson and her three children - 14-year-old Jamar, 12-year-old Minyan and 8-year-old Shanai.
The fire broke out around 1:30 Thursday morning in the 4800 block of North Palethorpe Street. Neighbors say they awoke to the sound of screams and crackling fire.
"We were woken up by the screams. It was the kids upstairs screaming," said neigbor Pedro Marquez.
They tried calling Wilson on her cell phone, but the only sound from the other end was the frantic pushing of buttons.
Firefighters arrived four minutes after the alarm went out, finding thick smoke and heavy flames pouring out of both floors of the house.
One of the firefighters had to be rescued when his foot went through a floorboard.
Investigators say at first a miscommunication led firefighters to believe that no one was in the house. It was not until the fire was out and crews went through the house that they realized four people were inside.
"They immediately attempted and interior attack. They were first told that everybody was out of the house. That seems to have been a miscommunication," said Fire Commissioner Lloyd Ayers.
Rasheeda's body was found in the front bedroom, while Jamar was found in a middle room. Minyan and Shani were found in a rear bedroom.
Ayres went on to say the fire caused an unusually intense level of heat and destruction. Because of that intensity, Ayers said this fire will be carefully investigated.
"At this point it is unbelievable," Ayers said.
He added that firefighters were distraught when they discovered the bodies.
"Right now everybody's heart is hurting - the firefighters and neighbors alike," said Ayers. "We're just a little upset right now."
Investigators have found only one smoke alarm in the basement and did not have a battery.
Neighbors say Wilson was well liked, was a block captain and was very active in her church. Neighbors were finding it hard to believe she is gone.
"I'm still trying to get over what happened. It's really scary that, suddenly, you're there and then you're gone," said neighbor Linda Kern.
The homes on both sides were also destroyed. A total of eight people are being helped by The Red Cross.