Girl Dead and Brother Hospitalized After Being Buried in Sand Hole on South Florida Beach

A young girl has died and a boy has been hospitalized after getting trapped in a collapsed sand hole at a South Florida beach.

The tragic incident occurred at around 3 p.m. local time on Tuesday after the two were playing in a sand hole that was 6-ft. deep n Lauderdale-by-the-Sea, authorities confirmed, per ABC News, CBS News and NBC 6 South Florida.

The children have since been identified as Sloan Mattingly, 7, and brother Maddox Mattingly, 9, according to the Broward Sheriff’s Office.

"The preliminary investigation revealed the children, and their parents were on vacation from Indiana," police said in their statement. "Investigators say the children were digging a hole in the sand when they were trapped. The circumstances into this incident remain under investigation."

It is not known how long the girl and boy were buried.

"Our deepest condolences are with the Mattingly family during this difficult time," the Town of Lauderdale By the Sea said in a statement on Wednesday.

Footage shared by CBS News Miami shows beach visitors and emergency responders attempting to rescue the children by digging them out of the sand.

Emergency crews eventually pulled the girl and boy out from the sunken hole as they used support boards to stop more sand from coming in on the children, reported ABC News.

The children were transported to Broward General Medical Center where the girl was pronounced dead, per ABC News, CBS News and NBC 6 South Florida.

The boy is currently in a stable condition, according to the outlets.

“It was an unfathomable accident,” King told the Miami Herald. “We were conducting life-saving techniques to try to bring her pulse back, and it never did recover, and she was pronounced dead at the hospital."

CBS News reported that some adults may have been helping the girl and boy dig the hole prior to its collapse, though they have not been identified.

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“I've lived here 50 years, I’ve never seen anything like that,” a resident told the outlet following the incident. “I’m shocked. I’m absolutely shocked. I had no idea that digging out … something could happen where it could collapse underneath someone just hanging out and playing on the beach.”

An investigation has now been opened following the incident, led by the Broward Sheriff's Office.

PEOPLE contacted the Broward Sheriff's Office for comment, but did not receive an immediate response.