Two girls and an adult missing since a huge explosion tore through a Nebraska biofuels plant are confirmed dead, officials said Wednesday, as firefighters were still battling smoke and flames smoldering in the wreckage nearly a day later.

Two girls, who were under the age of 12, and a man are dead after an explosion devastated a biofuels plant in Fremont, Neb. on Tuesday, July 29. Their bodies were not found until the next day.

Officials said the children were waiting for the adult, a plant employee, to finish work before heading to a doctor’s appointment.