Britons heading to the beach for the summer holidays have been ordered not to dig any big holes over a "risk of death".
Police have interevened to warn beachgoers not to burrow down deeper than knee level as the results could be dire.
People or pets could become trapped in the sand, they added, branding large holes in the sand "death traps".
In a statement on Monday, Skegness Police said: "Digging on the beach is part of the fun, but large, deep holes in soft sand can be incredibly dangerous.
"A hole can collapse without warning, trapping anyone inside under heavy sand in seconds."
Even "fit and healthy adults" can find themselves buried and unable to free themselves, police cautioned, advising the public to "keep holes shallow".
The warning comes after a huge hole was found on the beach at Skegness in Lincolnshire on Saturday.
Police shared images of the chasm online.
It measured roughly three to four feet across and between 12 and 15 feet deep.
HM Coastguard Skegness said: "Whoever dug this hole was incredibly lucky that it didn't collapse in on them.
"Sand is surprisingly heavy and can give way without warning, especially in deep holes."
Like police, the coastguard also stressed that such a collapse could leave someone buried beneath the sand, potentially causing serious injury or death.
They added: "Deep holes can also be a hazard to other beach users who may not see them."
BEACH WARNINGS - READ MORE:
- Man dies after getting into difficulty at Essex beach as emergency services rush to scene
- Iconic British beach considers using water cannons after surge in tourist fires and BBQs
- 'Do not touch!' British beachgoers issued warning over 'beautiful' blue sea creatures
Officers warned that big holes can ensnare children and adults enjoying the beach - as well as emergency responders if they're needed on the sand.
They said: "What takes minutes to dig can take seconds to turn tragic."
Police also ordered amateur diggers to fill in any holes before leaving the beach to keep the area safe for others.
This is not the first time beachgoers in Lincolnshire have created problems on the coast.
Last year, three coastguards were forced to fill in a more than two-metre-deep hole on Sandilands Beach.
In April, visitors to the popular seaside resort of Cleethorpes were also cautioned against digging in wet sand because of the "avalanche effect".
Coastguard deputy station manager Shaun Lee explained that sand can keep "collapsing" and end up burying people.
"We don't want to be the fun police just be aware of what you are doing if you are digging holes," he said.
Our Standards: The GB News Editorial Charter
