Thousands of bees swarmed over a busy San Francisco intersection and stopped service on a streetcar line for nearly two hours Friday until a beekeeper came to the rescue. A policeman said that when he arrived at the intersection the bees were "all over the place. There were thousands of them. They looked like an oil slick." The source of the swarm was unknown. Drivers abandoned their streetcars, traffic was routed around the intersection and pedestrians were kept from the area. Traffic was restored when beekeeper Simon Williams agreed to remove the bees for a $25 fee. "He just scooped the queen bee into a dustpan," said a streetcar official. "The swarm just dissipated after that.