Authorities in rural Ohio rescued 16 children from a severely neglected home where they had been confined to a single room for years in unsanitary conditions.

Officials said the children were found surrounded by human waste, with some unable to speak and one 18-year-old developmentally disabled girl unable to write her name.

The discovery was made during an unrelated search warrant in the small village of Hamden, and investigators said the children appeared to have been isolated from the outside world and not enrolled in school.

Vinton County authorities described the scene as extremely disturbing and compared the conditions unfavorably to those of livestock, the AP has reported.

The children’s parents and two grandparents have been charged with felony child endangerment as the investigation continues.