Authorities say 15 people were hospitalized after breathing in carbon monoxide at their church in Iowa, where a gasoline-powered generator was running in the basement to provide heat and lighting.

Medics and police officers sent around 2:45 p.m. Sunday to the Church of God in Marshalltown found several people inside with headaches and breathing difficulties. The first responders helped the churchgoers get treatment at a Marshalltown hospital. Eight of the victims later were taken to hospitals in Iowa City and Des Moines.