A construction worker died early Tuesday morning after falling 30 feet while installing girders for Sound Transit’s East Link project along eastbound State Route 520 near the 148th Avenue Northeast interchange.

Redmond police and the Bellevue fire departments responded to the incident. Medics performed CPR on the victim before he was later pronounced dead at Harborview Medical Center, according to Washington State Patrol trooper Rick Johnson, who was on the scene.

It is currently unknown why or how the victim fell, but Johnson said the Department of Labor and Industries is investigating the incident.

The East Link project has been assembling guide-way columns in Redmond’s Overlake neighborhood for the past eight days. The project will extend the East Link light rail from the Eastside to Northgate and Angle Lake.