Still, officials thought long and hard about whether to hold the event so soon, Mr. Sayed said. He was a little worried that the parents would stay away, only two weeks after the tragedy, with local and national governments still being battered nearly daily by public fury, revelations about lapses that made the tower vulnerable to fire and serial resignations of public officials. But the decision proved popular, and fairgoers of all ages filled the center and the blocked-off street outside.

With most of the Grenfell Tower survivors rehoused, for now, in hotel rooms, it was a welcome chance for them to take their children out somewhere and also see their friends and neighbors, Mr. Sayed said. “It’ll be good for the parents, too,” he said.

Ahmed Palekar, who had many friends in the tower, came to watch. “This is our way of talking about something else other than the fire,” he said. “But behind each smile is a troubled recent past.”

Amina al-Wahadi attended with her children and her sister, who escaped from a lower floor of the tower with her husband and two children. The sisters then watched as the flames engulfed the 21st floor, where their brother and his family lived; all five perished. The sisters were angry about how they had been treated by the authorities — “lie after lie after lie,” as Ms. Wahadi put it.