By Dan Gilgoff and Larry Lazo

Washington (CNN) - Washington’s National Cathedral sustained "significant damage" during Tuesday’s 5.8-magnitude earthquake, the church said Wednesday, and will remain closed at least through Saturday, when it had planned to host a dedication event for the capital’s new Martin Luther King Jr. memorial.

Three of the four corner spires on the church’s dramatic central tower lost their ornate capstones, or finials, during the quake, and there are cracks in some of the church’s flying buttresses.

Called the "Gloria in Excelsis,” the cathedral’s central tower is the highest point in the nation’s capital, rising to a greater height than even the Washington Monument.

The cracks in the flying buttresses are around the apse, the area around the altar, though the buttresses supporting the central tower appear to be sound, the church said in a statement.

Though the dedication ceremony for the Martin Luther King Jr. memorial has been moved to a Roman Catholic church in Washington, the Basilica of the National Shrine of the Immaculate Conception, National Cathedral officials said they hoped to host services Sunday.

The Rev. Samuel Lloyd, dean of the cathedral, said that there are no indications that the building has sustained serious structural damage but that structural engineers wanted more time to assess the building. “For safety’s sake, we want to be as careful as we can,” he said Wednesday, explaining the decision to keep the church closed.

“The good news is that this was not devastating,” he said. “It was quite serious, and there are some very important things we’re going to have to deal with, but it could have been much worse.”

Lloyd says he’s confident that the cathedral will go forward with three days of events around the 10th anniversary of the September 11 attacks.

"By that point, we will have had the time we need fully to assess what's going on,” he said. “All plans are full steam ahead."

Stonemasons and structural engineers are continuing to assess damage to the cathedral.

“We’ve been crawling all over the building since yesterday afternoon, and it just strikes me the amount of work that’s ahead of us,” the church’s mason foreman, Joe Alonso, said Wednesday. “Again, this is all handmade, this is a handmade building, and I just look at all of these little individual sculptures and works of art.”

“They’re delicate, but they’re still quite large,” he said. “When you look at those pinnacles up close, just knowing what goes into cutting and carving and laying these stones, we’ve got our work cut out for us. But we’re going to do it right.”

The quake struck at 1:51 p.m. Tuesday near the town of Mineral, Virginia, about 40 miles northwest of Richmond. Just 3.7 miles deep, it was felt from Georgia to northern New England.

No major injuries or extensive damage were reported, but the quake prompted evacuations of numerous office buildings – including the U.S. Capitol – and affected operations at a nuclear power plant in Virginia.

An Episcopal church, Washington National Cathedral considers itself a “spiritual home for the nation.” It is the traditional site for official presidential inauguration services and has hosted funeral and memorial services for 10 U.S. presidents.

According to its website, the cathedral was the longest-running project in the history of Washington. Construction began in 1907 and wasn’t completed until 1990.

“The earthquake which struck the East Coast today is a reminder of the continuing evolution of this planet, this fragile Earth, our island home,” said the Episcopal Church’s head, the Most Rev. Katharine Jefferts Schori.

“It is also a reminder of how interconnected we are,” she said in a statement. “The quake damaged Washington National Cathedral and reminded many Episcopalians of the quakes that struck the Christchurch Cathedral in New Zealand during the last year.”