The remains of a 9-year-old boy have been discovered in a Houston home along with three abandoned children, authorities said.

One of the children, a 15-year-old, said his 9-year-old brother had been dead for one year and his body was in the room next to his, Harris County Sheriff Ed Gonzalez said Monday.

The 15-year-old and the other two children — boys under the age of 10 — were found home alone on Sunday, the sheriff said.

Both younger kids “appeared malnourished and showed signs of physical injury,” he tweeted.

Deputies also “found skeletal remains of a small child,” the sheriff said.

All three children were taken to the hospital, he said. Their conditions were not released.

Authorities believe the parents hadn’t lived in the home for several months, Gonzalez said.

The children’s mother and her boyfriend were found late Sunday night, he said.

At a news conference Sunday Gonzalez called it a “horrific situation.”

“I have been in this business for a long time and I had never heard of a scenario like this,” he said.

The investigation is ongoing, the sheriff said.