As the first two floats caught fire, Sokka watched the smile slide from Aang's face, to be replaced by horror. Sokka grimaced, knowing what was next but forcing himself to watch.
The man hurled the torch from a nearby rooftop, directly into Float-Aang's eye. Real-Aang's eye squeezed shut – maybe unconsciously, but Aang obviously felt the pain.
Katara took off then, summoning a huge wave to put out the fires. All Sokka could do was stand beside Aang, squeezing his shoulder – but he did it gladly.
Knowing Aang – really knowing him – made it hard to understand how people could persecute him.