(CNN) -- Fire department investigators on Tuesday will interview the sole survivor of a Charleston, West Virginia, house fire that killed seven children and two adults over the weekend, according to Charleston police.
Latasha Jones Isabell, 24, was outside when the blaze consumed the two-story rental home. Isabell made an emergency call from a neighbor's house at 7 a.m. ET Saturday, authorities said.
"We do not have any reason to believe this is arson," Mayor Danny Jones said. "We believe it started in front on the bottom floor."
Though foul play is not suspected, the Charleston Fire Department is working with police to investigate the case.
A 7-year-old with critical injuries died Sunday morning after he was removed from life support at CAMC Women and Children's Hospital, according to Charleston police.
"We knew he wasn't going to survive," Jones said. "It was so hard, because we knew it the whole time, but we couldn't say anything."
Fire officials were surprised to learn the boy was alive when he was pulled from the inferno.
"I personally still believe in miracles, so I didn't want to count him out," said Assistant Chief Bob Sharp of the Charleston Fire Department.
City Building Inspector George Jarrett told the Charleston Gazette-Mail that rental homes are required to be inspected every two years.
The home was scheduled for a routine check late last month, but the inspector was asked to come back later, city officials said.
The home had only one working smoke detector, on the first floor, and it was incorrectly positioned, Jones said hours after the tragedy. It was on a counter rather than bolted to the ceiling. One other downstairs detector was not working, he said.
"Had we been able to get in that day and had we seen the fact they did not have the proper number of smoke detectors, we might have saved a lot of lives," Jones said.
All seven children were 8 or younger, and all were related, the city fire department said. Officials said the victims probably died from smoke inhalation.
Several of the victims lived in the house, Jones said, and the seven children and three adults had spent the night together after a birthday party for one of the adults Friday evening.
Jones said the building inspector arrived at the home February 28 after the landlord and the tenant had agreed to his visit. But a juvenile whom Jones described as half-asleep told the inspector that the tenant, one of the victims, was out car shopping.
The inspection did not occur, and the home was put back into a long list of residences to be visited. Inspectors check up to 40 homes a day, Jones said.
Residents sometimes remove batteries from detectors, officials said. And inspectors are not permitted to order residents to move if they find a problem.
"Most of our inspectors ... are turned away. 'Don't bother us.' To those people who have turned our inspectors away, at least check your smoke detectors," Jones said.
Downstairs areas need at least one smoke detector. Every bedroom should have a detector, as should hallways next to bedrooms, officials said.
Officials identified the victims as Alisha Carter Camp, 26; Alex Seal, 24; Keahna Camp, 8; Bryan Timothy Camp, 7; Jeremiah Camp, 3; Elijah Scott, 3; Emanuel Jones, 18 months; and Kiki and Gigi Seal, both 3 years old.
Authorities say the Seals were visiting from Pittsburgh.
Jones said that he "can't think of a more tragic event in Charleston's history" but that "one of the messages we get out of this tragedy is, we need these inspectors."
The Charleston Fire Department and local news and radio stations plan to hold a fundraiser for the fire victims Thursday and a "Never Again" smoke detector community event on Friday and Saturday.