San Francisco, California (CNN) -- All lanes on San Francisco's Golden Gate Bridge were closed Tuesday for about an hour as authorities responded to a multi-vehicle accident, according to Mary Currie with the Golden Gate Bridge District.
The accident happened at 9:02 a.m. (12:02 p.m. ET) near the toll plaza on the southbound side of the span.
At least five vehicles were involved, Currie said. The number and extent of injuries was not immediately available.
Head-on accidents are not uncommon on the iconic bridge, which has no center barrier dividing opposing traffic. Making matters worse, the lanes on the bridge, which opened in 1937, are more narrow than most.