The parents of a 2-year-old girl found Monday by police in a squalid Baton Rouge home suffer from drug problems fueled in part by grief over the death of the girl’s twin brother from accidental asphyxiation in 2014, the girl’s grandmother said Wednesday.

Police arrested the parents, Hollis Banks and Jasmine Rose, after discovering their young daughter alone in a soiled diaper in the couple’s Underwood Drive home about 2:40 a.m. Monday in conditions a Baton Rouge police officer described in a report as “extremely horrific.”

“I recognize what they did was wrong,” said Fran Banks, the 2-year-old’s paternal grandmother. “Overall, they’re good people, but drugs had a major part in that, a major part.”

The couple’s other child, Hollis Banks Jr., died at the age of 4 months as the result of asphyxiation while bed-sharing in unsafe sleeping conditions in August 2014, said Dr. William “Beau” Clark, the East Baton Rouge Parish coroner.

The child’s death was ruled an accident, Clark said.

It wasn’t clear if the Louisiana Department of Children and Family Services investigated the boy’s death or if the child welfare agency had fielded previous complaints about the parents. DCFS officials did not respond to requests for comment Wednesday.

An investigator with DCFS came to the home Monday morning to inspect the conditions inside and released the young girl to her grandmother, police have said.

Fran Banks, Hollis Banks Jr.’s mother, said she suspects grief over the child’s death and the passing of other family members more recently led the couple to struggle with addiction.

“They’ve been grieving, but they turned to drugs to numb the pain,” Banks said. “They started going down I think the last couple months of last year.”

Living conditions in the home, 4837 Underwood Drive, deteriorated quickly, Banks said. The last time she visited the house, when she went to pick up her granddaughter in December, there was food in the house and things seemed relatively tidy, though both Banks and a neighbor described the rental house as a poorly maintained slum.

“Had it been like that, I’d have snatched her myself,” Banks said. “We thought they were dealing with it okay.”

Monday morning, Baton Rouge police officers found animal feces, rotting food and drug paraphernalia strewn throughout the home, according to a police report.

A bail bondsman, stopping by the house on separate business, called police after finding the door open, the report says.

The two were arrested by officers when they returned home about an hour and a half after police arrived, according to the report.

They remain in East Baton Rouge Parish Prison on counts of cruelty to a juvenile, child desertion and criminal abandonment.

Both have previous brushes with the law.

Hollis Banks, 26, allegedly punched Rose during an argument in June in the waiting room of an Airline Highway urgent care clinic, where they’d taken their daughter for treatment, according to a Sheriff’s Office report.

Banks is charged with domestic abuse battery with child endangerment, a misdemeanor, in the alleged attack.

His mother said she hasn’t spoken with either since their arrest Monday morning.

“Right now, our main concern is” her granddaughter, Fran Banks said. “We’ll be taking care of her ourselves. The best thing for them is to go on and get the treatment and everything they need. It’s not going to happen overnight. It’s a process they have to go through.”

Nonetheless, Banks said she regrets the lack of treatment options and other support for those with drug problems outside of the criminal justice system.

“I know the state of Louisiana deals with a lot of cases pertaining to child neglect and child abuse, but they also don’t have enough programs out here to help the parents deal with addiction,” Banks said. “If they’d gotten the support they needed soon enough, they’d be alright. Because they didn’t, this is the consequence.”