There were no toys and no bicycles on the front lawn — only weeds that sometimes grew six feet tall.

Neighbors rarely saw the 13 siblings who lived inside the home in Southern California, because they never went outside to play. Instead, authorities said, they were held captive in a dirty and foul-smelling house, some of them shackled to the furniture with chains and padlocks.

Before dawn Sunday, a 17-year-old girl escaped from the Perris home, slipping through a window and dialing 911 on a deactivated cellphone, Capt. Greg Fellows with the Riverside County Sheriff's Department said Tuesday at a news conference. Per federal law, cellphones — even those that are no longer functional — must be able to call emergency services.

Deputies met the girl nearby and conducted a welfare check at the home, where they found a dozen others, age 2 to 29, in what authorities called "horrific" conditions.

Fellows said he could not provide details about the scene, but told reporters, "if you can imagine being 17 years old and appearing to be a 10-year-old, being chained to a bed, being malnourished and the injuries associated with that — I would call that torture." He said there was no evidence to indicate sexual abuse but noted that police are still investigating.

"We do need to acknowledge the courage of the young girl who escaped from that residence to bring attention so they could get the help that they so needed," he added.

These Sunday, Jan. 14, 2018, photos provided by the Riverside County Sheriff's Department show Louise Anna Turpin, left, and David Allen Turpin. Authorities say an emaciated teenager led deputies to a Perris, Calif., home where her 12 brothers and sisters were locked up in filthy conditions, with some of them malnourished and chained to beds. Riverside County sheriff's deputies arrested the parents David Allen Turpin and Louise Anna Turpin on Sunday. The parents could face charges including torture and child endangerment. (Riverside County Sheriff's Department via AP)

The biological parents, David Allen Turpin, 57, and Louise Anna Turpin, 49, have been arrested on charges of torture and child endangerment, according to authorities.

The Riverside County Sheriff's Department said in a news release Monday that the 13 siblings all appeared to be children, so deputies were "shocked" to discover that seven of them were actually adults.

They appeared malnourished and dirty and told authorities they were starving.

Authorities gave them food and drink, then the six minors were taken to Riverside University Hospital System Medical Center for treatment, according to the sheriff's department. The seven older siblings were taken to a different hospital.

Kimberly Trone, spokeswoman for the Riverside County Regional Medical Center in Moreno Valley, said Tuesday morning that the minors were admitted into the pediatrics unit for treatment Sunday but could not comment on their conditions. However, she noted that the patients, who range in age from 2 to 17, were taken to the sheriff's department before being transported to the hospital.

Corona Regional Medical Center spokeswoman Linda Pearson confirmed Tuesday that the seven adult siblings were receiving treatment at the hospital, but she did not elaborate.

Authorities said the parents were "unable to immediately provide a logical reason" why their children were shackled and chained and that the mother seemed perplexed by the investigation. Following an interview with police, they were arrested. Bail is set at $9 million each.

A public information officer for the Riverside County District Attorney's Office said no criminal case has yet been filed, so no court documents are available at this time. The couple is expected to be arraigned Thursday, so prosecutors have until then make a decision, he said.

David Turpin's parents, James and Betty Turpin of West Virginia, told ABC News they were "surprised and shocked" by the allegations. They said their son and daughter-in-law, whom they have not seen in several years, are religious and kept having children because "God called on them."

The grandparents said that the children are home-schooled, made to memorize long scriptures in the Bible. Some of the children, the grandparents told ABC News, have tried to memorize the entire book.

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.

Fellows, with the Riverside County Sheriff's Department, said Tuesday that authorities have no information about any involvement with any religious organization. He added that authorities had had no prior contact with the residents.

Fellows said the Turpins have lived in the city since 2014.

But according to public records, the couple own the home and have lived there since 2010. They previously lived in Texas for many years and had 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 on 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."

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.

Andria Valdez, a neighbor, told the Press-Enterprise that she had teased in the past that the Turpins reminded her of the Cullen family from the fictional series "Twilight."

"They only came out at night," she told the newspaper. "They were really, really pale."

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.

Mark Uffer, chief executive of Corona Regional Medical Center, said during the news conference that the adult siblings have been "friendly" and "cooperative."