Owners of Bawsey Pits are putting out another safety warning after people have been flouting the swimming ban and digging an unsupported cave formation.
Sibelco workers were shocked to discover the cave formation earlier this week and have destroyed it to prevent further tragedy.
Thursday marks the second anniversary of the second anniversary of the deaths of Lynn man Ryan Pettengell and 16-year-old Umar Balogun.
Safety patrols at the site are having little effect with people continuing to swim despite advice and children have been seen in the water.
Plans are progressing to sell the site and develop a safer country park in line with the findings of a public consultation that took place following the two drownings on July 16 2013.
Sibelco’s Lynn Site Manager Simon Mace is worried that people who are not prepared to wait for the improvements are taking an extreme gamble.
He said: “To be blunt we fear that someone else is going to die.
“We don’t know what more we can do. We have worked with the emergency services to increase the number and quality of safety signs and employed staff to patrol the site offering advice.
“Last summer we had people on duty 24 hours a day, seven days a week. But their advice is being ignored.
“And as for the sand caverns we discovered, they were terrifying, unspeakably dangerous. “Not only for the people who dug them but imagine a child finding them later. They could have wandered in, fascinated, completely unaware they could be buried alive at any moment.
“The police have advised us that unless an offence is being committed there’s nothing they can do.
“The two deaths in 2013 were devastating for all concerned, including my staff who have a real sense of duty to protect the public.
“Each day now they are coming to work, deeply concerned there will be another tragedy.
“The behaviour of some people at Bawsey Pits is not only irresponsible but also very selfish and we are pleading that something changes now before there’s cause for further regret.”