The fire last Tuesday evening at Ellsworth House, an apartment building for low-income seniors, could have been much worse. But Mercer Island firefighters were ready. The crew that responded to the scene knew all about the structure and its residents. As a result, they called for extra help to ensure that the residents would be safe and the building could be saved. Fire units from Bellevue and Seattle responded to the scene along with extra aid cars and ambulance units. Two Metro buses were called so that the residents who evacuated could be out of the cold.