One of nature's tiniest creatures has brought havoc to one of Charleston's oldest churches.

Termites have attacked the wood and skeletal support system at Citadel Square Baptist Church, the yellow stucco landmark adjacent to Marion Square.

The damage is so severe that the sanctuary has been closed for the last two years, forcing the tiny congregation to meet in an adjoining 1950s-era chapel.

That means services are being held in a far more informal setting than the old days when there was room for 1,000 people in the 1856-era nave.

Church leaders said it's a safety issue. The upper beam-and-support work — hidden from public view above the plaster ceiling — is so weak that for liability reasons, no one is allowed to sit in the pews below.

The fear is that even minor winds could cause enough vibration for plaster to break loose, crashing on anyone sitting below. The closure also means the church's pipe organ has gone silent.

While exterminators have treated where they can, some interior walls have been overrun, leaving visible cracks where the bug-munching broke through.

“We stuck our ears to the wall and we could hear them chewing,” Chris Union, the church's fundraising campaign director, said of one particularly busy area.

Early estimates indicate that minimum repairs could run $1 million or more — cash the dwindling church membership, down to about 70 active members, doesn't readily have. Neither is there insurance nor termite coverage.

Citadel Square's condition illustrates one of the many age-related issues facing Charleston houses of worship decades after original construction. Termites, though, have been a particularly troublesome plague.

As a port city, Charleston over the decades has offered easy pickings, made attractive when tainted cargo from overseas arrived. Hurricane Hugo in 1989 also is thought to have been a major contributor, as damp leaky roofs essentially became ringing dinner bells, attracting the fearless Formosan termite species.

It's happened before. At Bethel United Methodist Church, about a half-mile down Calhoun Street from Citadel Square, the final termite fix bill ran more than $3 million.

Reached last week, Bethel's pastor said he sympathizes with Citadel Square's troubles.

“When one church hurts, we all hurt,” Pastor John Warren said.

Citadel Square dates to the mid-1850s when area Baptists wanted to spread north from downtown toward the upper wards of the city. They opted for creating a new church from existing congregations. After construction, the site flourished, surviving the Civil War, an earthquake, hurricanes, tornadoes and steeple crashes.

While the church thrived into the 1990s, the congregation's numbers have aged and dwindled, partially because Charleston's younger families have fled for the suburbs while the neighborhoods around Calhoun and Meeting streets took on a more commercial slant.

Local preservationists have taken note of Citadel Square's plight. The Preservation Society of Charleston included the church on its annual “Seven to Save” list of endangered local structures.

Group Executive Director Evan Thompson said Citadel Square holds a unique position in the city's history, anchoring a street that in recent years has become a focal point of hotel building, business start-ups and entertainment. He hopes some of those investors might consider ways to help out.

“Millions of dollars of private investment is going into Meeting Street,” he said.

One avenue Thompson suggested is attacking church preservation as part of a collective effort. For instance, linking those congregations that need roof repairs, so that bids for replacements might be done under one umbrella if it can mean a lower price for all.

Charleston Mayor Joe Riley, who recently helped Redeemer Presbyterian Church on Wentworth Street escape becoming a private residence by lending his voice of support, said he plans to help “any way I can to engage the community” on Citadel Square's behalf.

The church has set up a fundraising campaign and is trying to locate craftspeople willing to help.

Pastor David Walker said he's optimistic. “I think the community will want to see the church remain intact with the skyline of Charleston,” he said.

For more information on Citadel Square Baptist Church, visit citadelsquare.org.

Reach Schuyler Kropf at 937-5551.