The Port of Seattle held a topping off ceremony Tuesday as the final structural beam of the International Arrivals Facility at Seattle-Tacoma International Airport was placed. The project is set to be finished in the fall of 2020 and have a 450K SF grand hall that will be five times larger than the current 1970s-era facility.

“We are on our way to creating a significantly better experience for our arriving international visitors and residents here at Sea-Tac and providing a much more welcoming facility reflective of our region’s quality,” Port of Seattle Commission President Courtney Gregoire said.

The airport continues to see growth in international airlines. In 2018, three new airlines began service, with three more scheduled for 2019. Over the last decade, the number of passengers requiring U.S. Customs clearances at Sea-Tac has doubled. During peak travel periods the number of passengers surpasses the amount that the facility was designed to hold, resulting in long wait times, according to a statement from the port.

This project is the most complex in the airport’s 69-year history. It will include an 85-foot-high aerial walkway that will connect passengers from the South Satellite terminal and a new security corridor that will allow dual use of gates on Course A for both international and domestic arriving flights.

The new International Arrivals Facility Program is expected to support approximately 10,600 new jobs, including 500 jobs a day during construction. Construction is set to be complete by May 31, 2020. The facility will be open to the public by the fall of that year.