The front yard of the house in the quiet neighborhood in Perris, California, was often overgrown with weeds nearly six feet tall. There were no toys, no bicycles in the front yard, neighbors said. More than a dozen children supposedly lived inside the home, but they never came outside to play.

On Sunday morning, authorities found 13 brothers and sisters held captive in the home, with several shackled to beds with chains and padlocks, "in dark and foul-smelling" conditions, the Riverside County Sheriff's Department said in a news release.

The siblings all appeared to be children, so sheriff deputies were "shocked" to discover that seven of them were actually adults, according to the news release. The ages of the 13 victims ranged from 2 to 29. They appeared malnourished and dirty, and told authorities they were starving.

One of them, a 17-year-old girl, managed to escape early Sunday morning, calling police on a cellphone she found in the home. "She appeared to be only 10 years old and slightly emaciated," the sheriff's department said in their news release.

The parents, David Allen Turpin, 57, and Louise Anna Turpin, 49, have been arrested on charges of torture and child endangerment. Their bail is set at $9 million each. They were "unable to immediately provide a logical reason" why their children were shackled and chained, authorities said.

Authorities interviewed the children and provided them with food and drink. The six minors were taken to a hospital and admitted for treatment, the sheriff's department said. The seven older children were taken to a different medical center and also admitted for treatment.

David Turpin is listed in a state Department of Education directory as the principal of Sandcastle Day School, a private K-12 school that he ran from the couple's home. The school opened in 2011, according to the directory. In the 2016-2017 year, the school enrolled a total of six students - one in each of the fifth, sixth, eighth, ninth, 10th and 12th grades.

According to public records, the couple own the home and have lived there since 2010. They previously lived in Texas for many years, and have twice declared bankruptcy.

The Turpins most recently filed for bankruptcy in California in 2011. According to court documents, David Turpin made about $140,000 per year as an engineer at Northrop Grumman. The couple listed about $150,000 in assets, including $87,000 in 401(k) plans from Northrop Grumman and Lockheed Martin. Louise Turpin's occupation was listed as a "homemaker." The couple owed debt between $100,000 and $500,000, according to bankruptcy documents.

One of their bankruptcy lawyers, Nancy Trahan, said in a phone interview with The Washington Post Monday evening that she met with the couple about four or five times in 2011, but hasn't seen them since then. She described the couple as "just very normal."

"They seemed like very nice people," Trahan said. "They spoke often and fondly of their children."

She did not recall hearing about a school run from their home.

"I just hope those kids are okay," Trahan said. "I wouldn't have seen it coming."

David Turpin's parents, James and Betty Turpin of West Virginia, told ABC News they are were "shocked" by the allegations. They said their grandchildren are home-schooled. They hadn't seen their son and daughter-in-law in four or five years, they said.

Photos on a Facebook page that appeared to be created by the parents showed the couple at Disneyland with the children wearing matching shirts. Several photos appeared to be taken at a wedding ceremony. The parents posed in bride and groom attire, surrounded by 10 female children smiling for the camera in matching purple plaid dresses and white shoes. Three male children stood behind them wearing suits.

The couple's middle-class neighborhood is a new tract housing development of ranch-style homes located about 70 miles east of Los Angeles. The homes were all built close together, with only about five feet between the houses.

Shortly after Kimberly Milligan, 50, moved to the neighborhood in June 2015, a contractor for the development told her the Turpins had about a dozen children, she said in an interview with The Post.

But in the years that followed, Milligan rarely heard the children and only occasionally saw three or four of the children briefly leave or enter the home. Milligan found this particularly odd, because their homes are only about 50 feet away from each other.

"I thought they were very young - 11, 12, 13 at the most - because of the way they carried themselves," Milligan said. "When they walked they would skip." They all looked very thin, their skin as white as paper, Milligan's son, Robert Perkins said.

And their yard would "always look in disarray," Milligan said. Code enforcement officials "cracked down" on the overgrown weeds in the front yard, several neighbors told media outlets.

Milligan recounted speaking to the children once, around Christmas 2015. Three of the children were setting up a Nativity display while she was out for a walk. When she complimented the children on the decorations, "they actually froze," she said. Milligan apologized, telling the children there was no need to be afraid.

"They still did not say a word," Milligan said. "They were like children whose only defense was to be invisible."

Milligan said she started seeing less and less of the family in the last year or so. She said she feels a bit guilty for not saying something about the family's oddities earlier.

"You knew something was off. It didn't make a lot of sense," Milligan said. "But this is something else entirely."

Law enforcement officers could be seen at the family's home from about 8 a.m. to 9 p.m. Sunday, Perkins said. He managed to briefly glance inside the open door of the home and noticed a messy array of boxes and chairs all over the place, he said.

One neighbor, Josh Tiedeman, told the Associated Press the children were "super skinny - not like athletic skinny, like malnourished skinny."

"They'd all have to mow the lawns together, and then they'd all go in," Tiedeman said.

Author Information: Samantha Schmidt is a reporter for The Washington Post's Morning Mix team. She previously worked as a reporting fellow for the New York Times.