Mayor Jim Gray said it appeared that years of deterioration caused a concrete panel to fall off the second story of a city-owned parking garage on Sunday.
Ron Jackson of R.E. Jackson Engineers inspected the Phoenix garage Monday and found that corrosion of a structural steel beam had caused the 28-foot panel to come loose, then crash onto a sidewalk on Vine Street. The deterioration was concealed in the drop ceiling of an electrical room.
"Clearly, it was a structural failure of significance," Gray said.
The other structural elements in the garage are visible, and there is no unusual deterioration in them, Gray said.
It does not appear as though a vehicle loosened the panel from the garage, said Tom Wilson, administrative officer in the Department of General Services for the Lexington-Fayette Urban County Government.
"I don't think a car hit it," Wilson said. "There weren't any cars on the top."
The garage and sidewalks surrounding it were closed Monday as crews assessed damage and built a temporary wooden guardrail. The garage will remain closed Tuesday. It is unclear when it will reopen.
Jackson's opinion was that the garage is safe to use, except for three parking spaces next to the missing panel.
However, Gray said Monday night that he is bringing in a second structural engineering firm, T.H.P. Limited of Cincinnati, to check the garage Tuesday.
"It's always good to get a second opinion," Gray said, adding the decision was not a reflection on Jackson.
T.H.P. already was planning to inspect the nearby Annex Garage on Tuesday.
Gray said he also had asked engineers from Gray Construction, his family's construction company, to assess the damage Monday. The city is not paying for that.
The garage, one of six owned by the city, had been scheduled for an inspection in July.
The last inspection of the garage was done by Desman Associates, a national architecture firm that specializes in parking garages, in 2005. The final report was submitted to the city in 2006.
That report noted that the bearing connections "that bear the full weight of the panels" had cracked in several areas. "Obviously the panels pose a threat to public safety if either the bearing or lateral connections failed," the report said.
The concrete panels weigh about 7 tons, according to the city.
After receiving the report, the city paid D.C. Byers Co. of Ohio $606,599 for repairs to the garage in 2006. Those repairs included "vertical wall repairs and soffit repairs," according to city documents. It wasn't immediately clear from the documents which walls were repaired and what was done to repair them.
"The corrective work was designed to fix, correct whatever problems existed, and in a sense create an overhaul," Gray said. "The real question is, how did they miss this condition?"
The Phoenix garage, which the city said is 30 years old, is used mostly by city employees and doesn't see much traffic on Sundays.
The incident was reminiscent of one that occurred May, 16, 2006. Stephanie Hufnagel, 22, who was eight months pregnant with her second child, was killed by a slab of concrete that fell from the privately owned Chase Bank parking garage.
That panel was knocked loose after it was struck by a slow-moving pickup on the second floor of the garage. The 5,000-pound panel broke away from its brackets and fell on Hufnagel, a bank employee who was walking below.
"The incident Sunday is a clear reminder that we need to make sure we inspect regularly and keep up with repairs, even when the budget is tight," Gray said.
The mayor said that he would evaluate the city's garage inspection schedule and repair record and that the incident raised questions about regulations governing privately owned garages as well.
"We're going to examine this issue carefully and see how this experience might translate into parking safety issues in garages across the city," he said.