Corrections and clarifications: The fire destroyed a building that housed executive offices at the Highlander Center. It was one of 10 buildings on the campus. The other nine structures were not damaged. An earlier version of this story was not specific enough about the extent of the damage.

A fire of unknown origin has destroyed the main office building containing decades of archives at the historic Highlander Education and Research Center in New Market, officials confirmed.

The fire initially was reported by a neighbor at about 5:30 a.m. Friday, New Market Volunteer Fire Department Capt. Sammy Solomon said.

The center became a key player in the civil rights movement of the 1950s and '60s, hosting figures such the Rev. Martin Luther King Jr., Rosa Parks and Eleanor Roosevelt at workshops and training sessions.

"While physically unhurt, we are saddened about the loss of our main office. The fire destroyed decades of historic documents, speeches, artifacts and memorabilia from movements of all kinds, including the Civil Rights Movement," Highlander's co-executive directors Ash-Lee Woodard and Rev. Allyn Maxfield-Steele said in a statement.

"Highlander has been a movement home for nearly 87 years and has weathered many storms. This is no different."

Crews arrived at the scene by 5:52 a.m. to find the wooden building engulfed in flames. "By the time they got there it was burnt to the ground," Solomon said.

The building, one of 10 on the center's 200-acre campus in Jefferson County, held offices for Highlander's executive leadership and program staff. The other nine buildings were not damaged.

"It was a building that held decades of archives ... files, irreplaceable items," said Chelsea Fuller, a communications strategist working on behalf of the Highlander Center.

"Luckily, nobody was inside and nobody was hurt. But it's devastating."

The building was equipped with a burglar and fire alarm system, which apparently failed to alert E-911, Solomon added.

The Jefferson County Sheriff's Office and state Fire Marshal's Office are investigating the fire's cause.

From the archives:Highlander Center spurned in curriculum changes

Founded in 1932 as the Highlander Folk School in Monteagle, Tennessee, the historic center is renowned for its social justice and leadership education.

The nonprofit has been at its current location in New Market since 1972.

According to a post Thursday on the center's Facebook page, the institution was set to break ground on a new Septima Clark Learning Center on its 200-acre campus next week.