[2] Dedication ceremonies were held on February 24, 1932,[3] and by April 1932, the final design for the Bay Bridge, including the single-bore tunnel through Yerba Buena Island, had been completed and submitted for approval.

[4] The contract to build the Yerba Buena Cable Anchorage, Tunnel & Viaduct segment was opened for bids on March 28, 1933, and awarded to the low bidder, Clinton Construction Company of California, for $1,821,129.50 (equivalent to $34 million in 2023[5]).

[8][9] Former President Herbert Hoover and Governor James Rolph were onsite; the two men were the first to turn over the earth with ceremonial golden spades.

[13] A subsequent California Department of Transportation (Caltrans) investigation identified 12 spots on both sides of the tunnel wall in the lower deck space showed signs of corrosion-induced damage, but no immediate risk of further spalling.

Caltrans engineers speculated the Masonite pads had swelled due to rainwater infiltration, cracking the tunnel walls and allowing moisture in to the reinforcing steel.

Drains and catch basins were replaced to reduce the likelihood of clogging, and fiberglass-reinforced mortar was used to patch removed concrete.

Purcell served as chief engineer for the Bay Bridge, including the construction of the Yerba Buena Tunnel.

[6] After excavating the western and eastern open portals, three drifts were bored from west to east along the path of the tunnel: one at the crown and the other two at the lower corners.

[16] A ceremonial party led by Governor Merriam celebrated the completion of the first 12-foot-square (3.7 m) drift on July 24 by walking through it, followed by a short speech.

As originally completed, the upper deck was reserved for automobile traffic, and carried six lanes, each 9 feet 8 inches (2.95 m) wide.

[29][30] The first accident caused by "The Hump", the nickname the bridge acquired after prominent warning signs advertising its presence, occurred just twelve minutes after it was first deployed on November 25, 1961.