PORTLAND, Ore. -- A 20-inch piece of grout fell from an Interstate 5 overpass Wednesday morning, shutting down the Rose Quarter MAX station and any trains that run under the Rose Quarter while crews inspected the scene.

Nobody was hurt when the grout fell and no structural damage was discovered, according to Oregon Department of Transportation Don Hamilton. He said the grout was probably loosened by road vibrations.

"The engineers found no issues of concern," he said. "All stable. No safety problems."

Hamilton said the grout will be replaced, but a schedule for the work has not been finalized.

The MAX Blue, Red and Green lines were restored shortly before noon.