No one was injured when the stone fell. The marble was part of the dentil moulding that serves as a frame for the frieze of statues atop the court's main entrance.
A group of visitors had just entered the building and had passed under the frieze when the stone fell at 9:30 a.m. EST.
Jonathan Fink, a government attorney waiting in line to attend arguments, said, "All of a sudden, these blocks started falling. It was like a thud, thud."
Ed Fisher, a government worker, said some of the marble pieces shattered, spraying the area with smaller chunks of stone. A group of students from Columbus, Ohio, pocketed some of the fragments as souvernirs, Fisher said.
Mark Goodman, a Washington resident, said some of the people who picked up larger pieces of stones took them back. "We'll have to look on eBay tomorrow," Goodman said.