Opening of the Golden Gate Bridge
The Golden Gate Bridge across the mouth of San Francisco Bay opened; its 1,280-metre main span made it the longest suspension bridge in the world at the time.

Chas. M. Hiller · Public domain · Source
Strong currents, thick fog and deep water made bridging the Golden Gate at the mouth of San Francisco Bay seem impossible. Work led by chief engineer Joseph Strauss began in 1933 and took four years; a safety net strung beneath the bridge is said to have saved nineteen workers who fell.
On Pedestrian Day, 27 May 1937, nearly 200,000 people walked across, and cars began crossing the next day. Its 1,280-metre span between the towers was the longest of any suspension bridge until 1964, and its “International Orange”, chosen to stand out in the fog, became its emblem.