OCALA, Fla. -- Investigators are still trying to determine what started a mobile home fire that killed a young mother and her four small children, the youngest just 2 months old.

An official with the Florida Fire Marshal's Office said investigators haven't yet found anything to suggest the cause of the fire is suspicious. He declined to release any further details.

Autopsies are still being performed to identify the five people killed in the Saturday morning blaze.

Family and friends believe they are a 25-year-old woman and four sons, ages 2 months to 6 years. Sandra Tuttle told the Ocala Star-Banner that her daughter, Tabetha Belanger, 25, perished in the fire, along with her sons, Hunter Belanger, 6, Nicholas Belanger, 4, Michael Belanger-Chase, who just turned 2; and Aron Chase Jr., almost 3 months old.

Grandparents of the children will be collecting financial donations to help with the burials.

Marion County fire officials said they received a call shortly before 6:45 a.m. from a person driving by the home on N.W. 20th Street.

A State Fire Marshall said the single-wide mobile home was engulfed in fire when the first units arrived, and the roof collapsed while units were battling the blaze.

Marion County firefighters found five bodies. The father wasn't home at the time of the fire.

Marion County firefighters said this was the highest number of deaths they had seen in a single structure fire in 20 years.