The new worldwide headquarters for Kiewit Corp. remains under construction but has reached its peak height — seven stories — and Omaha employees recently celebrated with a topping-off event.

Bob Kula, spokesman for the Fortune 500 company, said the topping-off occasion is common in the building industry when a new structure hits its tallest point.

Kiewit crews placed a ceremonial beam, signed by Omaha-based employees, atop the structure as one of the last steel beams installed.

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Workers now have moved on to precast work for the exterior of what is to be a 190,000-square-foot office structure. The parking garage for 550-plus stalls also is underway at the project site bounded by 15th, 16th, Cuming and Mike Fahey Streets.

That first phase is projected to cost up to $76 million, officials have said. Projected move-in date for up to 650 employees is early 2021.

Kiewit recently sold its headquarters since 1961, Kiewit Plaza at 3555 Farnam St., but will remain until the new digs are done.

Kiewit Building Group is doing “an excellent job managing the project and maintaining the schedule,” Kula said. A prime reason the construction and engineering company chose that north downtown spot for its global base is that its training center recently was built and opened across the street.

The new headquarters is seen as a key link that will connect TD Ameritrade Park and other developments to the east with Creighton University to the west. The Kiewit campus will be the anchor of the new and developing Builder’s District that ultimately is expected to stretch a dozen city blocks and usher in more than $300 million in investment.