Forty-six years ago – with just 72 days before the World’s Fair officially kicked off in Spokane – Tim Welsh climbed to the top of the incomplete U.S. Pavilion, popped the collar of his thick flannel jacket against the February chill and smiled for the camera. “All those cables you see, I measured every one of them. I did most of the surveying and layout of the project,” said Welsh, who was project engineer on the U.S. Pavilion for Expo ’74.