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.

The explosion occurred midday Tuesday at Horizon BioFuels, a manufacturer of fuel pellets and animal bedding located in Fremont.

The remains of two girls and a relative who were killed in a massive explosion at a Nebraska biofuel plant were recovered Wednesday after crews battled smoldering wreckage and an unstable building for more than 24 hours.