The incident occurred early Monday at the Municipal Center. Ambulances from neighboring towns, police and the entire Douglas Fire Department assisted those sickened, and their conditions were not considered serious, WCVB-TV, Boston, reported.
The Worcester Telegram & Gazette said 18 people -- including 16 kindergarten students at the Early Childhood Center, a teacher and a high school student working as an intern -- reported feeling ill. They were taken to a hospital for evaluation around 10:30 a.m..
"Douglas Fire and Police Departments are currently working with area towns to treat several people and children who have been subjected to CO2 in the Douglas Municipal Center at 29 Depot Street. The children have been removed to the elementary school and access is restricted in the area. Please plan your travel accordingly," police said in a statement.
The building was closed until the leak was found and repaired, and the structure was aired out. About 77 children were attending kindergarten at the Early Childhood Center.
The Municipal Center did not have carbon monoxide detectors, the newspaper said.