Answer: a car blowing up in our parking lot.
For a horrible five seconds, I thought the answer was that al Qaeda had gotten to LAX, but it looks like it was probably a loose fuel line. Someone in one of the other offices was starting her car, pumping gas onto the engine until it dribbled onto the spark plug. And WhooooOOOOOMP, the engine was on fire and black smoke was pouring off it. There was a mini-whoomp as the flames got to some other tasty morsel inside the engine. I spent about ten seconds staring at the fire extinguisher in the hallway, before deciding that the car was already a loss, and I didn't want to add myself to the loss column. Glenn had dialed 911, and the firemen got here in five minutes or so. By that time, the front tires and the interior were partially on fire. They hosed it down, sawed open the hood and drenched it some more.
Show's over; nothing to see. Move along.