A semicircular, 3 ft thick, 2.5 ft square of concrete fell into the path of a car on the eastbound lower deck of the Bay Bridge’s Yerba Buena Island tunnel recently. Jaxon Van Derbeken reports on the near collision from which the driver escaped unharmed.

Caltrans is now investigation whether or not corrosion is the reason behind the concrete chunk dislodging. Furthermore, Caltrans worries whether this means the rest of the 80-year old tunnel is corroding.

As of now this incident of corrosion appears to be isolated but Caltrans is further investigating the incident in order to keep commuters safe in the tunnel:


There are apparent water stains where the piece broke away, along with a crack where fractured concrete remains in place. There is evidence of more concrete cracking that is obscured by the tunnel ceiling.

“The possibility of water damage is one of the many factors that they are going to be investigating,” Haus said. “They are looking at the whole gamut of potential issues.”

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