Three kids went to a beach in South Australia to enjoy the sun, but they were never seen again.

Glenelg is a well-known beach town in the South Australian city of Adelaide. People come to the town’s sunny beaches in the summer to get away from the hustle and bustle of the city. But on a sunny day in January, darkness came to the shores of Glenelg.

It was Australia Day, January 26, 1966, and burning hot in Adelaide. The Beaumont children were on the way to the beach for a day’s swim. Jane, the oldest was 9-years-old and he was responsible for her younger siblings, Anna, 7-year-old, and Grant, 4-years-old.

The siblings got on a local bus at 10 a.m. to make the five-minute trip to the beach, which they had already done the day before. While their dad was at work, their mom Nancy spent the morning with a coworker. Nancy told her kids to come home by 2:00 p.m. so they could eat lunch.

When the time came and went and the kids weren’t on the bus, Nancy thought they had just missed it. But when the next bus came and the kids weren’t on it, the mother started to worry.

She phoned the authority quickly thereafter. The next day, the Beaumont kids were officially declared missing.

People who were at the beach on the morning the Beaumont children went missing said they saw the kids leave the beach at around 10:15 a.m. The next person who saw the Beaumont children was an old woman who said she saw them playing near a sprinkler about 45 minutes later. Still, this observer says that there was another person at playtime: a tall man with a slim build who was wearing a blue swimsuit. At first, this mysterious person was lying on the ground and watching the kids play. Still, the blond man got up soon after and joined the Beaumonts in their party.

At about 11:45 a.m., the kids were seen again at a nearby cake shop. Here, they bought sweets and used a £1 bill to pay for them. This was the first important sign for the police that something was wrong: the children’s mother would not have sent them off with that much money. They must have met someone who gave them the money.

The last sighting was made by a postman who knew the Beaumont family and was friendly with them. He said he saw the kids walking along Jetty Road away from the beach at around 3 p.m. This person said that the Beaumont siblings seemed happy, and the kids even stayed to say hello. The police did not think the mailman was trying to trick them. But the late afternoon time stamp surprised them because it didn’t fit with the order of the other sightings. They thought that the postman might have gotten the time wrong and that it happened first thing in the morning.

In either case, the children’s trail went cold after the postman said he saw them.

Australia was scared when the Beaumont children went missing, which sped up one of the biggest searches for missing people in the country’s history. No one could have drowned because all of their things had also gone missing. A request from Jim Beaumont was shown on TV all over the country. Police looked into every clue, but none of them led anywhere.

Paranormal detectives were even called in to help. Gerard Croiset, a well-known psychic and parapsychologist from the Netherlands, was flown to Australia. His call caused a big deal in the news. Croiset said that his sixth sense led him to a warehouse where he thought the bodies were buried. Even though the owners of the warehouse didn’t want to take part at first, they eventually raised $40,000 to have the building torn down. The site was dug up, but no bodies were found.

About two years after the kids went missing, their parents started getting strange letters saying that the kids were being held captive. The unknown author said he would bring the kids back at a certain time and place. The Beaumonts were happy, so they went to the place where they had agreed to meet, but no one was there.

A next letter reached quickly thereafter, declaring that because an undercover investigator had been present, the author withheld the children, and would now protect them forever. Twenty-five years later, the forensic analysis concluded the letters were a fraud.

The inquiry remains open to this day. A $1 million reward is offered to anyone with evidence that might crack the trial.

Nearly 50 years later, the problem remains: What happened to the three Beaumont children that hot day at the seaside?