JACKSON (AP) — Six children and three adults killed in a Mississippi apartment fire died of smoke inhalation, and their deaths were an accident, the coroner said Tuesday.

Investigators, meanwhile, were still working to figure out what sparked the blaze early Monday morning in the east Mississippi town of Starkville, killing several family members taken in because they had nowhere else to go.

Oktibbeha County Coroner Michael Hunt ordered autopsies on the three adults and said the children would have been examined if anything abnormal was found. Autopsies were not needed for the kids, he said.

The victims were India Williams, 25, and her three children, along with her cousin, Castella ‘‘Maria’’ Bell, 18, and her three children. The ninth victim was 20-year-old Lakesha Gillespie, identified by the West Memorial Funeral Home as a friend. The children were ages 6 months to 6 years.

Richard Vasser, the father of two of Williams’ children, had returned from Iraq on Christmas Eve to his base in Missouri and was traveling to Mississippi on Tuesday to prepare for the burial of his sons, said Vasser’s mother, Katherine Key.

Key said she was ill during Christmas and had not yet delivered the kids’ presents. She and her son were looking forward to visiting with them soon.

‘‘I lost my boys and it’s very, very hard,’’ she said.

Neighbors said Williams, who worked at a fast food restaurant, took in Bell and her children recently because they had fallen on hard times. They said Williams and Gillespie were a couple.

The Associated Press has been unable to locate relatives of Bell and Gillespie.

Ronald Williams, India’s cousin, said he can’t understand what went wrong because the two communicated on a computer Web site after 1 a.m., just hours before the fire, and everything was fine.

‘‘She was a kind person with a big heart and she loved those kids,’’ he said. ‘‘She was the type of cousin that if she saw me 300 yards away she would take off in a sprint until she got to me and give me a hug.’’

The apartment complex, Academy Crossing, is made up of six, two-story red brick buildings in Starkville, a city of about 24,000 full-time residents in eastern Mississippi that is also home to Mississippi State University.

It’s not clear how long it will take to determine what started the fire.

‘‘A fire investigation is like a puzzle,’’ Fire Chief Rodger Mann said. ‘‘We’ve got to get enough pieces of the puzzle to get a picture of what happened.’’

Some of the tenants told the AP that there were electrical problems in some of the apartments and that smoke detectors did not work.

The fire chief said a private company’s recent inspection found no troubles and Starkville Mayor Parker Wiseman said no one had reported problems to city code officials. Complex owner Mildred Rollins also said she was not aware of any such problems. She would not comment further.

The children killed were identified as Kamarion Williams, 2, Jacorian Vasser, 6, Richard Vasser, 5, Ta’Nayia Bell, 4, Jayvion Bell, 3, and Sumaya Bell, 6 months.

Funeral arrangements were incomplete Tuesday.