Old, "corroded" parts were one of the reasons that a silo filled with 500 tons of sand particles collapsed onto an 18-year-old worker in Loudoun County, Virginia in August, killing the young man, according to a federal investigation.
The investigation also found that the plant's owner failed to regularly inspect it for safety, according to a copy of the federal investigators' report reviewed by the News4 I-Team.
Daniel Potter, 18, of Front Royal, Virginia, was crushed and killed in the incident. The federal investigation was conducted during the past five months by U.S. Mine Safety and Health Administration.
Potter was unloading mineral filler, a fine, dust-line substance used in asphalt, from a silo before 6:30 a.m. Aug. 3, when that silo broke open, sending tons of the material rushing down.
"Management failed to take necessary follow-up actions to repair or replace components in order to maintain the stability of the structure," federal investigators said in their formal report.
The agency said a 2012 inspection cited an "area of concern" in the 56-foot-tall, 21-foot-wide silo and recommended changes be made and annual checks be conducted.
"This recommendation was never acted upon by the operator," the report said.
The investigation also said some of the bolts inside the silo were corroded, compromising the integrity of the structure.
Potter's father told the I-Team he'd received a copy of the investigation. He declined to comment on the report and said his family is not yet prepared to speak publicly about the death of his 18-year-old son.
Luck Stone, which is listed as operator of the quarry, released a statement saying in part, "We generally agree with MSHA's findings related to the structural cause of the silo failure. We are confident, however, that if anyone in our company had any idea that a failure like this could occur, we would have taken steps to correct it immediately."
Luck Stone said they have "have instituted a formal structural assurance program to better track the soundness and life cycle of our stationary structures." (Read Luck Stone's full statement here.)
The U.S. Mine Safety and Health Administration issued a citation against Luck Stone. The financial penalty for the citation has not yet been determined, a spokeswoman said.
"The process generally takes longer when a fatality is involved," she said.
Companies have a right to appeal citations and fines issued by the U.S. Mine Safety and Health Administration.
This story has been updated from an earlier version.