The Bay City Public Library turned spring break into a magical escape Thursday with its annual Harry Potter Book Day. The free family event ran in two sessions, from 4 to 5 and 5 to 6 p.m., with registration limited to 150 people per hour. Organizers transformed the library into a Hogwarts-style adventure with themed stations, games, and sweet treats like butterbeer. The city’s cultural arts director says the growing event showed the staff’s passion for blending fun with literacy.