Residents of a town about 15 miles (25km) away could hear the explosion, Sheriff Davis said on Friday.
One local resident who lives about 20 minutes away from the facility told the BBC she was sitting at her daughter’s dining table when she heard it.
“All of a sudden we just a heard a loud bang. We didn’t know if it was a gun or what,” she said.
Another local resident, Lucy Garton, who has lived nearby for six years, didn’t hear the explosion herself but she experienced the aftermath as she was on her way from work on Friday.
“When I came home, the roads were just blocked with state troopers. You had to show up proof that you lived here to get through,” she said. “There was a lot of ambulances, fire trucks, everything, parked down at the gas station.”
She said her husband knows people who worked in the facility.
“I think it will definitely impact the area,” she said. “It’s a very close-knit community and everyone, they’re just simple people, go to work every day, take care of their families and just real a family-oriented community.”
She said a lot of people in the area are employed at the plant, adding, “I’m sure it’ll be hard for them to go back to work after such a tragedy.”