SAN FRANCISCO (KGO) -- The last steel beam was placed on the Salesforce Tower today, making it the tallest occupiable building west of Chicago.
Salesforce CEO Marc Benioff held a ceremony to celebrate the completion of the structural phase.
Even though it's still under construction, it has been dominating the San Francisco skyline for quite some time. The tower at Mission and 1st streets has been under construction for four years.
It is 61 stories high and the developer, Boston Properties, says the building opening will be rolled out in phases starting in July through next year.
"The steels been finished, concrete finished, the skin of the building is coming up. In terms of later phases of construction, the building needs to be fit out for its tenants. So, each tenant that comes in, its space is going to be designed and constructed for its particular uses," Boston Properties spokesperson Michael Cantalupa said.
WATCH: Topping off ceremony to be held for Salesforce Tower in San Francisco
The Millenium Tower, which we know is sinking, is just a block away, but the big difference between the two buildings is that the Salesforce Tower is anchored to bedrock.
The iconic Transamerica Pyramid had been the tallest structure in the city for 43 years, but Salesforce Tower construction wiped away that record.
RELATED: Salesforce tower in SF becomes tallest occupiable building on West Coast
A new building in Los Angeles, the Wilshire Grand, has a spire that will be 30 feet taller than Salesforce, but at 1,070 feet, the Salesforce Tower will have the tallest occupiable floor.
Click here to watch construction of the Salesforce Tower.