CHARLOTTE, N.C. -- The engineers who looked at a SouthPark parking deck after it collapsed in May released a report Wednesday that says a bolt failed, leading to the collapse.

On May 13, just before 8:30 a.m., a section of a four-story parking deck collapsed at 6100 Fairview Road. There were no cars parked on the fourth-floor, where the structure failed.

The top section pancaked onto the other floors.

The report from the engineers says one bolt failed and a second showed signs of failure.

The engineers wrote that it appears the bolts that connected the beam to the column were not permitted to slide freely into the slotted connections. The slot was rough cut in the field during construction and clean-cut manufactured in a steel shop.

Because the bolt was not permitted to slid freely, through the years of expansion and contraction, coupled with corrosion, it led to failure of the bolt and ultimately the collapse.

The engineers are working to repair the parking structure and improve the bolted and welded connections. The engineers will submit the plans to Mecklenburg County for approval and they hope to have it finished by fall.

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