A school bus monitor is facing charges in the death of a 6-year-old Somerset County girl who was found unresponsive on the bus.

The Somerset County Prosecutor’s Office says Amanda Davila was charged with second-degree manslaughter and second-degree endangering the welfare of a child in the death of Fajr Williams on July 17. Officials say the child’s airway became obstructed by the harness of the wheelchair she uses.

Davila worked for Montauk Transit Service. News 12 spoke with the child’s parents on Wednesday inside their Franklin Township home. They say that they are devastated and can't stop thinking about their daughter and how much she probably suffered while fighting for her life.

“They need to know that when they take that job, they have lives in their hands,” says father Wali Williams.

Fajr Williams had Emanuel syndrome, a chromosomal disorder. This comes with some health conditions, such as epilepsy. She was also nonverbal and in a wheelchair. She was enrolled in an extended school year program at Clermont Elementary in Franklin Township.

Authorities say that Davila secured Fajr in her wheelchair at the back of the bus and then sat in the front of the bus.

“I know there is video that I have yet to view. But I will,” says mother Najmah Nash.

MORE: Authorities investigate death of child aboard school bus in Franklin Township

The investigation revealed that while on the road, a series of bumps caused the 6-year-old to slump in her wheelchair seat - making the four-point harness that secured her to the chair tight around her neck, ultimately blocking her airway.

“I am picturing her fighting. She can’t speak. She can’t defend herself. She can’t take the things off her neck,” says Wali Williams.

Authorities say that while this was happening, Davila was using her phone while wearing earbuds – a violation of policies and procedures, according to officials.

"I pray these people weren't playing on their phones while my daughter is back there fighting for her life,” says Wali Williams.

Nash says she called Montauk Transit Service after her daughter died, but she says the company was not able to provide her with any information.

News 12 New Jersey reached out to the company multiple times for a comment but did not hear back.

Davila is expected in court on Tuesday.