Witness to horrifying sand hole death of Sloan Mattingly says he wished he'd stepped in when he saw 'adults' digging pit that swallowed her up

A witness to the horrifying death of a seven-year-old girl trapped in a massive sand hole said he wished he had stepped in sooner to save the child. 

Harry Defina said he is still trying to wrap his head around the tragedy after Sloan Mattingly and her brother, Maddox, got trapped in the sand on a Lauderdale-by-the-Sea beach Tuesday. 

Sloan died after being buried inside the sand hole as her brother was rescued. He was taken to the hospital in stable condition.

'I see the kids in the hole. I could see the boy a little bit, but all I can see... I'm not going to be able to finish this...all I could see was the top of the girl's head,' Defina told NBC 6. 

'I saw the father was just beside himself.' 

'They didn’t dig that hole. It was massive and it ended up being like 18 feet by 6 feet,' he recalled. 

Seven-year-old Sloan Mattingly died after being buried inside a sand hole on Tuesday along a Lauderdale-by-the-Sea beach

The witness, Harry Defina, said that he saw the brother and sister trapped in the sand hole. He choked up and said that all he 'could see was the top of the girl's head'

Frantic beachgoers got on their knees and dug with their hands in a desperate attempt to reach the girl

Sloan was pulled out 20 minutes after the sand caved around her and her brother as dramatic cell phone video captured the moment frantic beachgoers attempted to dig her out. 

The girl's grieving uncle, Chris Sloan, said the young girl kept trying to hold on to Maddox's leg to get out of the sand but eventually the boy could not feel her holding onto him anymore.

'She was always happy. She was really fun to be around. She had a lot of energy and just totally innocent, and that's what hurts the most in all this.

'They were having a good time. They were staying at an Airbnb. Everybody was really excited to actually see them out there.

'They don't really go on vacation much, but they went to Ft. Lauderdale to the beach.

'They'd been posting pictures the last couple of days they've been out there on social media.

'I got a text message as did everybody on the group chat to call a number for a conference call.

'Once we all got on the line, my brother, David, said, "Ok. What I have to tell you is going to be the worst news of your entire life".

'And it was. He said that she had passed away, that Sloanie had passed away,' Chris told KFOR. 

'The sand had been up to his [Maddox] chest, and he was screaming for help, and a lot of people did come and help. There's actually some video of that. 

'She was non-responsive at the scene is what we know,' he added.

Sloan's older brother Maddox  who was trapped in the hole with her, was able to be rescued.  He was taken to hospital in stable condition after also being injured in the collapse 

The scene of the tragic event is seen blocked off by cops, tape and orange cones around the big hole 

Sloan Mattingly's grieving uncle, Chris Sloan said the young girl kept trying to hold on to Maddox's leg to get out of the sand but eventually the boy could not feel her moving anymore

A panic-stricken witness was heard in the video telling a dispatcher how Sloan's mother the mother Therese was desperately yelling: 'My daughter is in there.'

'Everybody's screaming' the caller continued, as people cried out in the background: 'They do not see her head, they do not see her.' 

Separate audio of the 911 dispatcher alerting officers to the beach noted that around 20 bystanders had rushed to join the efforts to dig the girl out of the sand.

The person who initially called 911 began by telling the dispatcher there was 'a bunch of people trying to dig.' 

She said she realized something was wrong when she heard 'the father yelling for help', who 'said his child is caught in a hole in the sand.'

Panicked screaming and yelling can be heard in the background of the audio, and the woman who called 911's voice broke as she warned the dispatcher: 'They have not gotten the child out yet.'

Sloan was eventually pulled out of the sand, but tragically succumbed to her injuries and was pronounced dead on arrival at hospital.

She did not have a pulse when she emerged from the sand and was declared dead at the hospital, according to officials. 

Her mother recently said the family has been 'forever changed' following the tragedy and that the GoFundMe page set up for the family has raised more than $146,00. 

'A freak accident happened yesterday while we are here on vacation and it took away our greatest 7.5 years,' Therese said on the page. 

'Don't tell us you're sorry for our loss… don't do that to us. We experienced the purest human being and we are forever changed by her. 

The family is seen on another holiday a few years back in a photo posted to Facebook. Sloan's mother (right) said that their family has been 'forever changed' following the tragedy 

A moment of silence is set to be held in honor of the little girl at the Friday Night Music concert and at the Town Commission Meeting on Tuesday. Flowers have already been placed on the beach in memory of her

'We love you beyond any stretch of the imagination. Our sweet Sloan. What we would give.'

A moment of silence is set to be held in honor of the little girl at the Friday Night Music concert and at the Town Commission Meeting on Tuesday. Flowers have already been placed on the beach in memory of her. 

Officials said that along with a tribute to Sloan, the incident will be discussed at the meeting, including the topics of lifeguards and ordinances. 

'The sad news that seven-year-old Sloan Mattingly passed away earlier this week has left our entire community heartbroken. Our deepest condolences remain with the Mattingly family during this difficult time,' the town said in a statement. 

Although sand hole deaths are very rare, they are not unheard of and there have been studies and warnings published about them.

According to Dr. Stephen Leatherman from Florida International University's Department of Earth and Environment, deep sand holes can be a death trap. 

The expert explained that once a person's body's is below the sand level, sand starts drying out immediately. 

'When people dig holes more than two feet deep and get in them, at least where their body's below the sand level, sand starts drying out immediately.