Authorities in Somerset County are investigating the death of a 6-year-old girl that occurred on a school bus Monday morning.

The Somerset County Prosecutor’s Office says that the office and the Franklin Township Police Department are investigating the incident but did not provide further details.

News 12 New Jersey spoke with the child’s family, who say that they are devastated by what happened.

“There’s no words to express how we feel at this time. We’re barely holding on,” says Najmah Nash, the child’s mother.

Nash says that her daughter has Emanuel syndrome, a chromosomal disorder. This comes with some health conditions, such as epilepsy. The girl is also nonverbal and is in a wheelchair.

Nash says that she received a call from the school around 9 a.m. Monday that her daughter was unresponsive, and that CPR was underway. She says her daughter made it to the hospital but died.

She says she called the bus company Montauk Bus and spoke to the bus aide about what happened. The aide told her that she did not know why the girl became unresponsive.

Nash also says that she was later told by a detective that the bus aide was arrested and charged in connection to the death. News 12 has not been able to independently confirm this.

News 12 has reached out to Montauk Bus for a comment but did not hear back.

It was not immediately clear how the girl died.