San Francisco Chronicle reports, “Safety concerns, including worries over terrorism, are prompting Golden Gate Bridge authorities to consider a proposal to close all northbound lanes of the iconic span during the upcoming San Francisco Marathon. . . . It would be the first such closure for the bridge in the history of the marathon, which will celebrate its 40th anniversary with the July 23 run that is expected to draw about 15,000 runners. . . .” The Golden Gate Bridge district board will vote on the lane closing proposal today.