The Martin Luther King Jr. Memorial may not be ready for the 50th anniversary of the March on Washington later this month.
Workers had been removing a disputed inscription from the memorial, but an architect says a contracting problem has stalled the project.
Architect Ed Jackson Jr. tells The Associated Press the side of the memorial's "Stone of Hope" is unfinished because the main contractor doesn't have insurance to complete sandblasting to refinish the stone surface.
Workers accidentally stained it a brownish color Friday during an alternate blasting process.
National Park Service spokeswoman Carol Johnson says the work may have to stop for the anniversary of the march on Aug. 28 and resume later. Or the agency could use its own workers to do the sandblasting to finish it sooner.