Report: CO 11202016-0318 A carbon monoxide alarm from a home in Wellesley was received and firefighters immediately dispatched to the address. Then our Central Station operator called the residence, awakened the homeowner and urged him to get everyone out of the house. Upon arrival, first responders confirmed high levels of the potentially deadly gas in the home. They traced the source of the gas to the home’s fireplace, which had been in use that evening. No injuries reported.