I think this article has special meaning in SF...
http://www.sfgate.com/cgi-bin/article.cgi?f=/c/a/2009/06/05/BAG8181NH5.DTL&tsp=1
The blast happened about 11:30 a.m. near Polk and O'Farrell streets in front of the Mitchell Brothers O'Farrell Theater. Flames and a plume of thick black smoke billowed from a manhole, and the smell of burning plastic hung in the air as firefighters sprayed foam into the manhole.