Can you tell me about the time Sai Baba climbed a roof to help a sick devotee?

Certainly. Chapter 19 recounts a miraculous event where Baba helped Radhakrishnabai. One day, Baba, who was so physically weak he usually needed two people to support him, suddenly asked for a ladder. He had it placed against Vaman Gondkar's house, quickly climbed to the roof, and crossed over to the adjacent roof of Radhakrishnabai's house. At that very moment, Radhakrishnabai was suffering from an extremely high malarial fever and was very restless. After this mysterious act, Baba climbed down and the fever presumably subsided, showcasing a miracle where he overcame his own frailty to aid a devotee in distress.