A large granite stone fell from the corner of the historic Frick Building in downtown Pittsburgh early Sunday morning, crashing into the crosswalk below.
In a release, the mayor's office said Grant Street will remain closed from Fifth and Fourth avenues until at least midday Tuesday. Without an engineers' report, officials couldn't be sure what caused the 1,300-pound stone to fall from underneath the building's southwest cornice; water infiltration is suspected.
It's not uncommon, said Glenn Foglio, president of Graciano Corporation who is working for the Frick Building's ownership.
"These buildings are all 100 years old. The design is ... faulty, just generally, because of what construction was at that time," he said. "The steel is packed with the cement and the mortar, doesn't have room to breathe, water gets in, the freeze thaw starts and rust moves the stone, cracks the stone."
The building facade had no violations, said Maura Kennedy, director of the Department of Permits, Licenses, and Inspections. Shortly after the event was reported, around 2 a.m. Sunday, police cordoned off the area. No one has been hurt.
Director of the Department of Public Safety Wendell Hissrich said the event occurred at the best possible time, early in the morning. "If it had been in the afternoon, or in the morning, we might be here talking about a tragedy. That's why we're here, taking all the appropriate precautions."
"This corner won't be totally safe until that is completely encapsulated in steel scaffolding," said Foglio, adding he expected to begin building it Monday.
The engineers report also begun Monday.
The building is named for industrialist Henry Clay Frick who had it built along with several others downtown. It opened in 1902.
The 20-story building stands about 330 feet high. The building houses law offices and other commercial tenants.
The Associated Press contributed to this story.