Waterbury fire fighters were dispatched for a structure fire at 307-309 Bishop St. As they rolled to the fire it was evident that they would be working as smoke billowing from the vacant apartment building could already be seen for miles. With the building well involved 2 ladder trucks were positioned for a defensive attack and additional companies were requested to stretch in supply lines as well as assist companies already operating on the scene. Approximately 20 minutes in the roof and second floor collapsed pinning fire fighters on the flat roof of one of the exposures. After several tense minutes all were accounted for and it was determined that none of the men were seriously injured. After almost an hour and a half of pouring water into the structure the main body of fire would be knocked down. Even though the adjacent structure was effected by the collapse it appeared that none of the exposures suffered and extensive damage. Fire crews would remain on scene dousing any hot spots and representatives of the City's fire marshal's office were on scene to investigate the scene.