Friendsville, Blount County (WVLT) - Investigators say the cause of a fire that killed four children just outside Friendsville was electrical in nature.
However, it's unclear if wall space heaters installed more than 30 years ago were a factor.
But even if they aren't responsible, officials say these kinds of heaters are no longer in code and can be dangerous.
Fire killed four members of the Debuty family early Tuesday morning. Fire officials only say it was electrical in nature and started in a bedroom.
The home builder says he put a heat source in the bedrooms.
"When I built the house, I put wall heaters in it," say Harold Wolfe, who built the Debuty's home.
While it's unclear if they played a role in the fire, many older homes still have such heaters.
"They should be concerned," says Mike Day from the Wholesale Supply Group.
Officials at Wholesale Supply Group in Maryville say those old wall heaters are no longer up to code.
"They've been discontinued for many years. The UL [Underwriter Laboratory] no longer lists them and they're no longer manufactured," says Day.
Day says there's a good reason the heaters are no longer in code.
"Safety. There is an element that gets red hot and anything that gets close to it can easily combust," says Day.
Wall heaters are still made, but Day says they are much safer. "Is a fan forced heater. The element no longer gets red hot and it warms up and the fan blows it and it's more efficient."
Fire officials say the best defense against fire is the smoke detector. Because of Tuesday's tragedy, they are stepping up fire safety efforts going to all the schools, stopping by Friendsville School to start.
"Let's contact all the teachers of the schools and get them to contact the students, parents by phone and say, 'Do you have a working smoke detector?'" says Blount County Fire Chief Doug McClanahan.
Funeral arrangements are set for the four Debuty children killed in the fire.
The family will receive friends from four to seven p-m on Monday at Smith Mortuary. The funeral is set for two p.m. on Tuesday at Smith Mortuary, with burial immediately following at Grand View Cemetery.