Bethel Fire & EMS responded to the smell of gas in a commercial complex Friday afternoon.  Danbury Fire Department responded to a mutual aid request for a ladder truck when a rooftop unit was suspected as the cause.  Eversource Gas responded for the investigation at Dolan Plaza as well. EMS provided evaluations of business employees. The problem was isolated to a rooftop HVAC unit, and the building was determined to be safe to occupy.