McEWEN, Tenn. (AP) — Officials were investigating a blast that leveled an explosives plant in rural Tennessee, as families of the 18 people missing and feared dead waited anxiously Saturday for answers.

The explosion Friday morning at Accurate Energetic Systems, which supplies and researches explosives for the military, scattered debris over at least a half-mile (800-meter) area and was felt by residents more than 15 miles (24 kilometers) away, said Humphreys County Sheriff Chris Davis.

Aerial footage showed the company’s hilltop location smoldering and smoky Friday, with just a mass of twisted metal, burned-out shells of cars and an array of debris left behind.

Davis, who described it as one of the worst scenes he’s ever seen, said multiple people were killed. But he declined to say how many, referring to the 18 missing as “souls” because officials were still speaking to family.

“What we need right now is we need our communities to come together and understand that we’ve lost a lot of people,” he said.