Marlow Fire Department Chief Ryan Hall says it happened at a home in the 200 block of E. Arapaho just before 4 a.m. Saturday.
He says two people died: one adult and one child, but their names are not being released at this time.
Several other people were able to get out of the home and were not injured.
It took firefighters more than four hours to put out the blaze.
Hall says investigators have ruled out arson as a potential cause, so the fire is now being looked at as accidental.
He says officials will continue looking for the exact cause and they hope to know more early this week.
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