Tampa engineer explains sand hole that killed 7-year-old girl in South Florida

Girl dies in Florida sand hole, raising alarm

After a young girl died while digging a sand hole at a Florida beach, a Tampa engineer is explaining the dangers of sand.

TAMPA, Fla. - A family's beach vacation turned into tragedy on Tuesday when two siblings were digging a deep hole in the sand, and they were suddenly trapped underneath it.

The 9-year-old boy survived, but his 7-year-old sister didn’t make it.

"The boy was about maybe 3-feet down, but his head was above sand, but his sister was down further, and they tried to dig her out, but the more they dug, the more the sand collapsed," a bystander told WSVN.

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As officials now warn not to dig deep holes at the beach, a geotechnical engineer in Tampa Bay explains the impact of this collapse, and why the depth was dangerous.

"If this hole reached five feet deep, to be safe or have a person in it, it would have to be laid back with a "safe slope" that would make it 10 to 20 ft. across at the top," explained Henri Jean.

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"For every foot you go down into the ground, you put 110 pounds per square foot of depth, so at five feet deep the amount of soil that would be on top of you would be about 550 pounds per square feet. The combination of the weight and the lack of oxygen would result in a very bad situation for anybody down there," Jean said of the potential impact to the little girl.