RICHMOND, Va. (AP) — Crews in Virginia ended a daylong search Thursday after they were unable to locate a 134-year-old time capsule state officials believe is buried in the pedestal of a statue of Confederate Gen. Robert E. Lee that towered over Richmond for more than a century.

State officials were scheduled to remove the 1887 time capsule from the pedestal a day after the massive statue was taken down. But after removing more than half a dozen large, heavy stones, crews were unable to find it.

Workers used ground-penetrating radar devices, a metal detector and other construction equipment to try to locate the copper time capsule they believed was tucked inside or under a cornerstone of a 40-foot (12-meter) tall granite pedestal that the bronze equestrian statue of Lee had been perched on since 1890.

The statue was hoisted off its pedestal on Wednesday, more than a year after Gov. Ralph Northam ordered its removal in June 2020 after protests over racism and police brutality erupted across the country following the police killing of George Floyd in Minneapolis.

While the removal of the statue went quickly and smoothly, the search for the time capsule was marked by difficulties and frustration. Crews had to remove three separate pieces of the cornerstone weighing between 500 and 8,000 pounds (225 and 3,620 kilograms) each. They also removed a half dozen other large stones around the perimeter of the pedestal so they could search under the cornerstone and the area around it.

After about 12 hours of work, crews ended their search for the day, said Northam’s chief of staff, Clark Mercer. Mercer said workers planned to return Friday to put the stones they removed back in place and to insert a new time capsule in the cornerstone. He said it is doubtful workers would resume looking for the 1887 time capsule, but left open a small possibility.

“It’s disappointing not to find the time capsule,” he said.

“We looked where we thought it was. It doesn’t preclude (us) in the future from finding it, but for right now, the mystery will continue.”

Dale Brumfield, a local historian and author who has conducted extensive research on the time capsule, said he is sure the capsule is located somewhere in the pedestal, citing a newspaper account of an 1887 dedication ceremony that drew thousands of people.

“I’m positive there’s a capsule in there somewhere,” he said. “We just can’t find where.”

A newspaper article from 1887 suggests the copper time capsule contains mostly memorabilia, including a U.S. silver dollar and a collection of Confederate buttons. But one line from that article has piqued the interest of historians. Listed among the artifacts is a “picture of Lincoln lying in his coffin.”

It is unclear what kind of a picture it is, but the article says it was donated by “Miss Pattie Leake,” who was a school principal from a prominent local family.

Harold Holzer, a historian and Lincoln scholar, told The Associated Press earlier this year he believes it’s highly doubtful the picture is an actual photograph of Lincoln in his coffin because the only known photo of Lincoln in death was taken by photographer Jeremiah Gurney in City Hall in New York on April 24, 1865.

Holzer said it’s more likely it could be a popular Currier & Ives lithographic print of Lincoln lying in state in New York or a sketch done by someone who may have witnessed Lincoln’s body during a two-week tour the president’s body was taken on before his burial in Springfield, Illinois.

The new time capsule to be placed Friday contains items reflective of current events, including an expired vial of the Pfizer COVID-19 vaccine, a Black Lives Matter sticker and a photograph of a Black ballerina with her fist raised near the Lee statue during last summer’s protests in Richmond.

The Lee statue was one of five enormous Confederate tributes along Richmond’s Monument Avenue and the only one that belonged to the state. The four city-owned statues were taken down last summer, but the Lee statue removal was blocked by two lawsuits until a ruling from the Supreme Court of Virginia last week cleared the way for it to be taken down Wednesday.