Pillow enthusiasts collided yet again on Saturday in Washington Square Park for the tenth annual International Pillow Fight Day. The event started promptly at 3 p.m. with participants (including a lot of kids) pummeling each other with sleeping instruments. The participant to photographer ratio was about 3:1, but the spectator to participant ratio was an even 1:1. Click through for plenty of photos and videos of the feathered casualties.