The Richmond-San Rafael Bridge over San Francisco Bay was shut down in both directions Thursday after football-sized chunks of concrete fell from the upper deck of the bridge onto the lower deck, authorities said.

A driver called 911 around 10:30 a.m. to report that pieces of concrete had struck a car, California Highway Patrol Officer Andrew Barclay said. The driver said the vehicle was damaged, but the traveler was on the way to the airport and kept on driving, Barclay said.