The Ferry Building, that long, tall landmark where Market Street meets the Embarcadero, is where they brought the injured after the great San Francisco quake of 1906. It's the hub that drew as many as 50,000 commuters daily across the bay before there were any big bridges here, then sent them back across the water at day's end. It's the monument that a freeway amputated from the rest of the city in the 1950s, its clock tower left to jut into the fog like a forgotten gravestone.