Understanding Irony in a Statement

In a small town, the mayor decided to hold a grand celebration for the opening of a new playground. Flyers were distributed throughout the town, and families were encouraged to bring their children to enjoy the festivities. On the day of the event, however, a sudden rainstorm hit the town, forcing everyone to stay indoors. As the mayor stood in the empty playground, soaked from the rain yet smiling, he declared, “Well, at least the children won’t get to break anything on this first day!”

What type of irony is illustrated in the mayor's statement?