Charleston County school leaders effectively condemned six downtown school buildings Thursday after hearing engineering reports that most of the structures couldn't withstand a 5.0 or greater earthquake.

Given that information, School Superintendent Nancy McGinley said the district has a moral imperative to investigate the possibility of relocating more than 1,300 students and their teachers into open buildings elsewhere in the county as soon as this summer.

"I know this is a serious issue," she said, "but the safety of our students is our No. 1 priority."

Schools that would be affected are Buist Academy, James Simons Elementary, Memminger Elementary and Charleston Progressive Academy. The Archer building, which has been used as a temporary site for Sanders-Clyde School, and Fraser Elementary, which the board closed last year, also were cited as having significant seismic deficiencies, but neither is housing students.

McGinley plans to present a relocation plan for the four occupied downtown schools by March 22, and district leaders will hold meetings with parents during the next two weeks to explain the seismic reports. The nine-member school board ultimately will decide whether to move downtown students or allow them to stay put.

The district doesn't know how much the seismic repairs would cost or how it would pay for them, but officials estimate it would take at least three years to complete the work and return students to peninsula schools. School leaders plan to give the board cost estimates within the next month, and they also will calculate the price tag for demolishing and rebuilding the schools.

The seismic reports come at the same time the school board was poised to decide whether to pursue a bond referendum this fall. They hadn't decided which construction projects would be included in the next building program, but McGinley said she would recommend that these be included. All of this could factor into some voters' decision on whether to support a tax increase for school construction projects.

This isn't the first time the school district has cited seismic problems as a reason for prohibiting students from using a building. The Charleston Charter School for Math & Science wanted to locate in the former Rivers Middle School campus downtown, but engineers' analysis showed significant seismic problems, and school officials said no one should use the space until those were addressed. The charter school occupies mobile units on the former school's campus, but it does not use the main Rivers building. If money remains from the ongoing building program, the school board has agreed that at least $25 million would be used toward repairing it.

The school board requested the seismic reports for the district's downtown schools this past fall because those structures are at greatest risk should an earthquake strike. The buildings are multiple stories with unreinforced masonry, and they stand on poor soil, said Bill Lewis, executive director of the district's building program. Lewis has said for years these schools would be dangerous places during an earthquake, and the engineering reports presented to the board on Thursday confirmed the buildings would partially or completely fail in a significant earthquake.

An earthquake rated at a 5.0 on the Richter scale is considered to be "small"; the devastating 1886 earthquake in Charleston was 7.3, rating between "strong" and "major" on the same scale.

Seismic problems aside, engineers told the board that the buildings were in good condition and didn't present an immediate threat to students. Still, none were designed to weather a serious earthquake.

Lewis acknowledged the report may cause angst among parents, students and teachers, but he said most communities that face this type of earthquake threat dealt with these issues three decades ago.

Mark Brandenburg, a parent of two Buist Academy students, said he doesn't see his children's lives being any more at risk than they were before the reports were made public. He understood district leaders' concerns and said they ought to have a response, but he said he'd rather see them take time to develop a solution.

"It seems like they're in an awful rush," he said.