What is a sand holes? Florida professor warns of dangers after girl's death

The collapse of a sand hole that killed a 7-year-old Indiana girl who was digging with her brother on a Florida beach is an underrecognized danger that kills and injures several children a year around the country.

Sloan Mattingly died Tuesday afternoon at Lauderdale-by-the-Sea when a 5-to-6-foot-deep hole collapsed on her and her 9-year-old brother, Maddox. The boy was buried up to his chest, but the girl was fully covered.

What is a sand hole and why can they be dangerous?

A sand hole is what it sounds like — a hole in the sand. Plenty of beachgoers, especially children, enjoy digging as deep as they can. But the bigger the hole, the more dangerous it can be.

Dr. Stephen Leatherman from Florida International University's Department of Earth and Environment told NBC Miami that deep holes can be a "death trap." If you're gonna dig a hole in the sand, make sure it's no more than two feet deep.

"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," Leatherman said. "And dry sand can only hold a 33-degree angle, and people dig these holes almost vertically."

At that point, the sides of the hole can start caving in and it can cave in very rapidly. Leatherman also pointed out the risk of someone stepping on the edge of a hole before the sand dries out and causing a massive collapse.

"The deeper the hole, the greater the risk," Leatherman said.

Rescuing from a sand hole

Trying to rescue someone from a sand hole is very difficult, Leatherman said.

Video taken by a bystander on Tuesday at Lauderdale-by-the-Sea shows about 20 adults trying to dig Mattingly out using their hands and plastic pails, but the hole kept collapsing on itself.

Lauderdale-by-the-Sea does not have lifeguards at its beach, so there were no professionals immediately available to help. The first deputies arrived about four minutes after the collapse, with paramedics and firefighters arriving moments later, according to 911 calls released by the Broward County Sheriff's Office on Wednesday.

A spokesperson from the Pompano Beach Fire-Rescue Department said rescue crews took over for the bystanders, using shovels to dig out the sand and boards to stabilize the hole, but when they got to the girl, she had no pulse.

"People think it's like snow avalanches or something," Leatherman said. "It's really quite different. An avalanche, people have been saved. Snow is kind of light. An avalanche occurs, and the snow can be a little blocky and there are gonna be air pockets. There are no air pockets in sand."

Sand can easily move around you and is very heavy.

"Trying to find somebody to recover them is very, very difficult and almost impossible," Leatherman said.

The statistics of sand hole deaths

"We don't hear much about it, but nationally, there have been a large number of people who have died in sand hole collapses," Leatherman said.

News reports and a 2007 medical study show that about three to five children die in the United States each year when a sand hole they are digging at the beach, a park or at home collapses on top of them. Others are seriously injured and require CPR to survive.

Those who died include a 17-year-old boy who was buried at a North Carolina beach last year, a 13-year-old who was digging into a sand dune at a state park in Utah and an 18-year-old who was digging with his sister at a New Jersey beach. Those two accidents happened in 2022.

“The risk of this event is enormously deceptive because of its association with relaxed recreational settings not generally regarded as hazardous,” the New England Journal of Medicine study concluded.

How to stay safe

Sand is fun to play with, and Leatherman recognizes that.

"But you shouldn't be digging holes," he said. "If you dig holes — no deeper than two feet, and cover them up when you leave. Keep it shallow and you don't have a problem of collapse."

He urges parents to monitor the size of any holes kids are digging and to stop them if they start to get deep.

"We all like to play in the sand," Leatherman said. "But if you play in sand, (make) sandcastles and very shallow holes."

Lifeguards say parents need to be careful about letting their children dig at the beach and not let them get too deep.

Patrick Bafford, the lifeguard manager for Clearwater, Florida, said his staff will warn families if a hole gets too big but sometimes they aren't noticed in time.

“We have had events where people have had close calls or died because of a collapse,” he said. “You want them to have fun, (but) there’s a difference between fun and a hazard they might face. It’s hard really for people to understand that the beach can be a hazard. Bad things can still happen no matter what. Use good judgment."

Shawn DeRosa, who runs a firm that trains lifeguards, said “many people don’t think through the risks in allowing children to dig deep or wide holes."

“They know that the sand might slide down or that a wall could collapse, but they don’t seem to envision their child being buried in the sand so quickly,” he said. "Nor do they appreciate the real challenge in getting the child out of the sand once the collapse has occurred.”