Sorry Tourists and Nob Hill historic transit fans: Bay City News reports the Powell Street Cable Car lines are currently out of commission until further notice. Muni officials spotted a problem with one of the cables this morning and will be running shuttles along the route in the meantime. Sure, a shuttle bus isn't nearly as much fun to ride as a rolling historic landmark, but it's better than getting caught on a runaway, explosive cable car:

[BCN/Appeal]