Hypersmurf
Moderatarrrrh...
It was more like, I dunno, Ghostbusters than an actual horror movie.
Heh. I played in a Scooby-Doo Dread game, and watched part of a Breakfast Club Dread game, and there was plenty of creepy to go around along with the comedy

But people take for ****ing ever to pull pieces sometimes, and it's really hard to actually narrate something interesting while they're doing it.
Try to gauge the mood of the players.
I found that sometimes, the GM would tell a player "Make a pull", or even "Make five pulls", and everyone else would be feeling "Okay, but what about us?", and the GM would continue on with a "Meanwhile" for another character or group of characters. The pulling player would let the GM know when he was done, and whether he'd succeeded or bailed. (If the tower actually falls, of course, everyone notices!)
Other times, the GM would say "Make a pull", and everyone at the table (and often the unrelated players at the next table) would be so riveted on the tower that attempting to carry on with a "Meanwhile" scene would be futile. It's easy to spot when the table is in this mode - if the tower moves very slightly, and you hear a simultaneous hiss of breath from all sides, they're feeling it...
-Hyp.