At around 9 a.m. Monday, Katonah Fire Department was dispatched for an inside gas investigation at William Green and Company on Katonah Avenue. Engine 116, Ladder 39, and Car 2213 responded. Crews immediately got to work evacuating the structures, and then checked the buildings for readings. When elevated gas and CO readings were discovered, Car 2213 requested Engine 198 from Bedford Hills Fire Department for mutual aid to assist with the multiple buildings that needed checking. Meanwhile, Engine 116 tied into a nearby fire hydrant, and Ladder 39 raised its aerial to the roof. A call was made to expedite Con Ed to the scene. After approximately an hour, the cause was determined to be a problem with a gas stove. Units were back in service by about 1030. Katonah Fire Department extends its thanks to Bedford Hills FD and Battalion 16 for their assistance.