The first explosion, sounding like a muffled crump, could be hear over the stereo indoors. And I'm easy 10 blocks away! There were several more over the next few minutes. Only after I enlarged these photos did I notice the people standing on neighbouring rooftops, watching the whole espisode!

Interesting to watch the crowded skies. Three different helicopters hovered overhead, while a single-engined plane did loops around the scene. Even after the last of the smoke had died down, they would still come back... I guess checking on how/when streets were being unblocked?

Thankfully, no one was killed, which still amazes me. For details, see the story on www.sfgate.com

As always, take care
John.