Hear that whistle blowin'

Last night, just around midnight, there was the loudest thunderclap I've heard since leaving Mid-West. It was a rolling, surging boom that sounded so much like a freight train that I had to check out my window (after it had subsided) to make sure a tornado hadn't torn away the backyard.

After the crest, the thunder echoed for a good minute longer. It was so out of the ordinary for San Francisco's impossibly tranquil climate that I'm surprised there aren't more reports of it.

The sky was falling, people!