The bus had just arrived at the library when the alarm went off, said Tamara Bethke, a student intern from Grand Valley State University and a classroom assistant.
The Peach Plains Elementary School students were instead bused over to Duncan Memorial Park until they were allowed to return to the library.
Assistant Library Director Kerry FitzGerald said there was a problem with a heating and cooling sensor in one of the study areas, which set off the alarm.
Grand Haven Department of Public Safety officers checked the building and an all-clear was given at 9:48 a.m.
Children’s librarian Marilyn Painter said they were planning to put on skits as part of the program to introduce children to the library. The program is given to all first-graders in the area.