SAN FRANCISCO—The last steel beam was placed on the Salesforce Tower on Thursday, April 6, making it the tallest occupiable building west of Chicago, ABC 7 news reported. Salesforce CEO Marc Benioff held a ceremony to celebrate the completion of the structural phase.

While building is still under construction, it has been dominating the San Francisco skyline. The tower at Mission and 1st Streets has been under construction for 4 years. It stands 61 stories high and the developer, Boston Properties plans on the building’s opening to be presented in phases starting in July 2017 into 2018. 

Before the last beam was put into place, a sacred tradition (known as one of the oldest rituals in construction), resulted in a “Topping Off” ceremony.  A 14-foot-long beam, covered with the signatures of workers and notable attendees was hoisted 61 stories to the crown of the tower. Attached to the steel beam was a 6-foot tall cedar tree.

The arboreal tradition dates back to ancient Scandinavia where, after a timber-frame structure was complete, a tree was placed atop the new building in to assuage any tree-dwelling spirits uprooted during its construction.

One of the tallest office buildings west of Chicago stands at 1,070 feet, where it holds the title of the Tallest Occupiable Building. The other title belongs to the Wilshire Grand in Los Angeles, which added a spire bringing its height to 1,099 feet.

The Transamerica Pyramid was the tallest structure in the city for 43 years. The Transamerica Pyramid and 555 California, measuring at 853 feet and 779 feet respectively are no longer the city’s tallest towers.

Written By Casey Jacobs and Deanna Morgado