The girl who died after a 5- to 6-foot deep sand hole collapsed on her and and her brother Tuesday afternoon at Lauderdale-by-the-Sea has been identified by the Broward Sheriff’s Office.

She is 5-year-old Sloan Mattingly, and her brother, Maddox Matttingly, is 9 years old, BSO said Wednesday afternoon.

The children and their parents were vacationing from Indiana, the sheriff’s office said in a statement. The children had dug the hole by the shore, authorities said.

“It was an unfathomable accident,” Pompano Beach Fire Rescue spokeswoman Sandra King said.

On Tuesday, Pompano Beach Fire Rescue paramedics, after digging the two children out of the sand on the beach at 4424 El Mar Drive, rushed the girl to the Broward Medical Center in Fort Lauderdale, where doctors pronounced her dead, according to King.

Broward Sheriff’s Office deputies took the young boy to the hospital in stable condition, said King. It was unclear whether he was still in the hospital Wednesday afternoon.

Firefighters and deputies were dispatched to the beach around 3:15 p.m. Tuesday When firefighters arrived, nearby Good Samaritans were trying to help dig them out.

The boy was chest deep in the sand before firefighters were able to rescue him. His parents subsequently ran him to a BSO car, and deputies took him to the hospital, according to King.

But the girl, who was submerged beneath him in the sand for an unknown period of time, was still trapped.

Firefighters then used tools like shovels and supportive boards in an attempt to reach the girl without the hole further collapsing in on her, added King.

By the time they rescued her, though, she was no longer breathing. King noted that paramedics’ attempts to revive her en route to the hospital were unsuccessful. Upon making it there, King confirmed she was pronounced dead.

“The circumstances into this incident remain under investigation,” BSO said in a statement.

This story will be updated as more information becomes available.