A Southern California couple are in custody after one of their daughters contacted 911 and led authorities to their home, where 12 of her siblings were inside, including "several children shackled to their beds with chains and padlocks in dark and foul-smelling surroundings."

The discovery in Perris, Calif., came after the 17-year-old daughter — who police described as emaciated and appearing to be just 10 — escaped the home of her parents, David Allen Turpin, 57, and Louise Anna Turpin, 49, on Sunday and called police with a cell phone she found at the residence.

The Riverside County Sheriff's Department said in a statement that the 13 victims – the youngest just 2 years old — were so malnourished that officers "were shocked to discover that 7 of them were actually adults, ranging in age from 18 to 29."

The parents told police that six of the couple's children are minors and seven over the age of 18, according to The Associated Press.

The victims, the statement said, "appeared to be malnourished and very dirty."

When police arrived "the parents were unable to immediately provide a logical reason why their children were restrained in that manner," according to the statement.

The couple were arrested on Sunday and each charged with nine counts of torture and 10 counts of child endangerment. They are each being held on a $9 million bond.

Police provided food and drink to the children, "after they claimed to be starving," the statement said.

A home where a couple was arrested after police discovered that 13 people had been held captive in filthy conditions with some shackled to beds with chains and padlocks, on Monday in Perris, Calif. BILL WECHTER/AFP/Getty Images

All 13 victims were taken to hospitals for examinations and treatment, the sheriff's office said.

Public records, cited by The Los Angeles Times, "show the couple own the tract house where the children were found. Its address is also listed in a state Department of Education directory as the location of the Sandcastle Day School, a private K-12 campus. David Turpin is listed as the principal."

David Turpin's parents, James and Betty Turpin, of West Virginia, told ABC News that they were "surprised and shocked" at the allegations because their son and daughter-in-law were "a good Christian family" who homeschooled the children. They said they had not seen the family since visiting California four or five years ago.

The Times, citing public records, reports that the couple had moved to California from Texas several years ago and that they had declared bankruptcy twice.

Ivan Trahan, an attorney who had represented the couple in their most recent bankruptcy filing, in 2011, was quoted by the Times as saying that the Turpins seemed like "very nice people who spoke highly of their children" but who had fallen into financial problems.

Trahan said David Turpin had worked as an engineer for Northrop Grumman. A spokesman for the defense contractor confirmed to the Times that he was employed there until 2010.

However, Kimberly Milligan, 50, who lives across the street, was quoted by the newspaper as saying that when she first moved in she saw a woman outside the house with an infant, but eventually stopped seeing the child. Over the years, Milligan said, she would occasionally see three children who looked like preteens.

"I thought the kids were home-schooled," she said. "You know something is off, but you don't want to think bad of people."

Considering the proximity of the houses, Milligan questioned aloud: "How did no one see anything?"

Milligan was quoted by Reuters as saying that two years ago around Christmas she saw three of the older Turpin children outside and complimented them on a nativity scene outside their house. She said they "froze [as] if by doing so they could become invisible.

"[Twenty-year-olds never act like that," she told the news agency. "They didn't want to have a social conversation."