Horry County, SC – A build-up of propane gas inside an Horry County house is to blame for an explosion that killed a Rock Hill couple, Horry County fire officials report.

June and Ray Harder died in the blast, which occurred at 2:08 a.m. Sunday.

The single-story house at 4949 S.C. 472 was so damaged by the explosion officials will likely never know what ignited the gas, Todd Cartner, Horry County Fire Rescue spokesman, said Tuesday.

“Because it was so blown apart, it’s really hard to determine the ignition source. [The house] was completely destroyed,” Cartner said.

Investigators reported finding debris as far as 124 feet from the house.

Cartner said the source of the propane was a 500-gallon tank about 100 feet from the house.

He said finding the leak that filled the house with the gas is also practically impossible.

“If you can find the piece of copper tubing that bulged and eventually leaked, that’s one thing, but there’s just no way to find it with how completely destroyed everything was,” he said.

The couple who owned the house, 46-year-old June and 47-year-old Ray Harder, have a permanent residence in Rock Hill and were in town for the weekend getting the house ready to rent, said June Harder’s brother, Michael Houghes.

No one else was injured in the explosion and no other structures were damaged, Cartner said.

Cartner stressed the importance of having a professional propane handler inspect tanks annually. In addition to risk of explosion, propane leaks also can create carbon monoxide, which is odorless, tasteless and deadly, he said.

Officials on Tuesday also released the cause of a separate fire last weekend in the Floyds community.

An electric hot water heater caused the fire at 3204 Labor Camp Road about 7 p.m. Sunday, Cartner said.

That blaze caused extensive damage inside the house, but the outside of the home is largely intact, Cartner said.

The family who lived there, two adults and two children, will be unable to return for quite some time, according to Cartner, who said the American Red Cross is assisting them. There were no injuries reported in that incident.