Posted: May. 10, 2017 12:01 am

The three boys routinely explored caves in Hannibal's Southside neighborhood. They used the Hoag family's aluminum ladder to reach cave entrances not easily accessible — mud from Hannibal's underbelly caked on the rungs. Like many neighborhood children, eager to find adventure like the fictional characters enshrined in Mark Twain's stories set in Hannibal, they sought exciting action underground.

Armed with flashlights and a shovel (or so witnesses saw) the three boys set off on May 10, 1967, presumably intent on finding another adventure like Tom Sawyer or Huckleberry Finn.

But on this day, they didn't return home.

Suppertime passed and the three kids still hadn't returned from the caves, sparking a massive search that drew national attention for the next ten days as the Hannibal community awaited word on the fate of the three youngsters.

Despite an enormous and expensive effort, the three children were never found.

The disappearance of Billy Hoag, 10, Joey Hoag, 13 and Craig Dowell, 14, remains one of Hannibal's greatest mysteries 50 years after the trio entered the sprawling Murphy's Cave complex.

Or did they?

In the 50 years since the trio seemingly vanished, rumors and theories have swirled about their fate.

Did they enter Murphy's Cave?

Did they become trapped in another cave as the result of the construction of Highway 79?

Were they in a cave at all, or had they run away from home?

Or, even darker still, had they been kidnapped and taken away from Hannibal?

On Wednesday, May 10, 1967, Lynn Strube, age 14, reportedly saw the boys headed in the direction of Murphy's Cave around 4:30 p.m., flashlights and a shovel in hand.

Strube's account was, at the time, the last known sighting of the boys. The boys also passed a fire station, en route to the cave.

Much of the rescue efforts focused on Murphy's Cave, a sprawling cave system with an entrance near Birch and Walnut Streets. Once the boys were considered missing, the Mark Twain Emergency Squad responded first, but the search soon evolved into a national rescue mission with hundreds of spelunkers descending on Hannibal in a frenzy to locate the missing boys.

The National Speleological Society was brought in by Presidential Jet 2, with William Karras in charge of the search, according to Courier-Post reports.

Often working late into the night under the glare of floodlights, the entire town mobilized to locate the Hoag brothers and Dowell, a childhood friend.

But by the third day without anyone seeing the boys, doubts arose that the boys were indeed inside Murphy's Cave.

Perhaps they had become trapped in any number of small caves discovered while crews blasted the area to build Missouri Highway 79. Several of those holes had been sealed, and fear grew as another frantic search began to locate those holes and unseal them.

"Friends came forward and said that the boys, and other boys of the South Side had been entering these holes in late afternoon after the construction workers left for the day," wrote J. Hurley and Roberta Hagood in their book, Hannibal Yesterdays. "This kind of activity would require daring and would have appealed to boys in spite of the great danger."

As options for the boys whereabouts expanded, so did the search.

The Courier-Post reported on May 12, "Mayor Harry Musgrove requested that the National Guard begin a search this morning from the Universal Atlas Cement Plant at Ilasco north along the river to a point beyond the cave area."

Trains leaving Hannibal after 4:40 p.m. On May 10, 1967, were searched for signs of the boys.

As the Hoag and Dowell families clung to hope, people from across the country provided tips and leads to police and rescuers, who poured hundreds of thousands of dollars into the rescue effort.

The Courier-Post reported tips ranging from a stray sock found near a cave entrance to a mysterious red substance believed to be blood by another.

Letters poured into the Hannibal Police Department, asking crews to scour islands in the Mississippi River.

Hope briefly rekindled at the sighting of adolescent boys in the St. Louis area. They turned out to be from Cape Girardeau.

Clairvoyants and psychics from as far away as California and Arizona contacted rescue officials with their premonitions. One relayed a recurring visions of the boys locked in a rail car with oranges bound for an unknown destination in the U.S.

Leads led to dead ends.

Every abandoned house in the city's South Side was searched and a large-scale combing of the woods surrounding the area took place.

Ten days after the boys disappeared, the preliminary search was called off.

Shorter, localized searches were launched in the next few days, but by the end of June 1967, official searches ceased.

A community mourned the unknown fate of the Hoags and Dowell, a mystery that broke the hearts of people then and baffles them now.

"I'm at as much a loss as to why God put this mystery before us as anyone," Karras, leader of the search mission, told the Courier-Post.

The tragedy has sparked interest for many, including C.W. Stewart, who penned A Sorrow of the Heart, the Story of Hannibal's lost three little boys, which published in 2010.

During construction of the new A.D. Stowell Elementary School in 2006, crews uncovered the entrance to the cave, rekindling memories of the three boys. The cave held no trace of the boys, another dead end almost 40 years after the tragedy.

The mystery continues today, leaving people wondering if a trace of the boys sits somewhere beneath Hannibal, waiting for the moment when another cave entrance or passageway illuminates a puzzle unsolved after 50 years.

Reach editor Eric Dundon at eric.dundon@courierpost.com .