If the huge parking garage being built behind the Rivers Casino on the North Shore seemed a bit out of kilter recently, your eyes didn't deceive you.

Parts of the nine-level garage were found to be leaning by nearly a foot, prompting intervention by the U.S. Occupational Safety and Health Administration and a plan of action by contractors to straighten things out.

Despite the problems, OSHA found the garage to be "safe and structurally sound," Acting Area Director Frank Librich said yesterday. "At no time during erection were employees in danger of a building collapse."

The agency became involved after receiving an anonymous tip in February saying that floors seven through nine in the garage were out of plumb, or leaning.

OSHA investigated the next day and determined that about 80 columns on the three floors were out of plumb. Mr. Librich said seven columns were off by as much as 8 to 111/16 inches. The vast majority of the rest were off less than 5 inches, he said.

By the time OSHA arrived, the casino's contractors already had developed a remediation plan to straighten out all of the columns using cables and tensioning devices, Mr. Librich said.

Since then, all but one column line have been brought back to plumb "in accordance with design specifications," he said. It should be finished in about two weeks.

"It could have been a serious issue, but it wasn't," Mr. Librich said.

He said he did not know what caused the columns to lean. But he added the problems appeared to start after crews, which had been erecting the pre-cast concrete used on the garage from left to right, shifted the crane and began erecting from right to left.

Rich Stanizzo, business manager of the Pittsburgh Building and Construction Trades Council, said it was not unusual for structures to be slightly out of plumb as they are being erected. But parts of the garage were out of alignment a "little bit more than normal," he said.

Nonetheless, he was confident that the remedial measures "are correcting the problems."

Workers have been under a tight schedule to get the casino and the garage completed by August. All work stopped for about a month last summer after Detroit businessman Don Barden failed to secure permanent financing for the slots parlor. A group led by Chicago billionaire Neil Bluhm then took over the project.

Mr. Stanizzo said he didn't think the fast pace had anything to do with the alignment issue, adding that you "can only go so fast" in erecting precast concrete.

In a statement, casino spokesman Dan Fee said the garage, which has been a source of controversy because of its size, "is structurally sound and remains safe."

"During the construction of all multilevel structures, it is not uncommon to make adjustments to bring all floors into alignment and final position. That is what is occurring now," he said.

The casino, he said, is still on track to open in August.

Mr. Librich said the casino faced no fines as a result of the problem because there were no violations of OSHA standards. Overall, the site has been a safe one, he said. Mr. Stanizzo said incident and accident rates had been below normal for such a large job.