A coroner says six children and three adults killed in a Mississippi apartment fire died of smoke inhalation, and their deaths have been ruled an accident.

Investigators, meanwhile, were still working to figure out what sparked the blaze early Monday morning in the east Mississippi town of Starkville.

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

The children ranged in age from 6 months to 6 years.

Relatives said Richard Vasser, the father of two of the 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.

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