AUGUSTA, Maine (AP) According to legislative testimony, a post placed in the ground severed an underground propane line leading to a deadly explosion in Maine.

Two people explained the cause of the Farmington blast to a committee Tuesday as part of a public hearing regarding a proposed modification to the state’s “dig safe” law.

The September explosion killed a firefighter and injured several others.

State fire investigators were expected to release their findings Thursday. Dig Safe Laws prohibit digging around certain underground utility lines, but not liquefied propane gas lines. The head of the Propane Gas Association of New England said businesses shouldn’t be subjected to unnecessary costs and that numerous trainings are held on avoiding propane lines.