Cumberland County Deputies and Crossville Police are actively searching for three persons, two adult males and one adult female, who attempted an armed robbery this afternoon at a residence on Darrell Avenue in Crossville.  The three suspects are thought to be in the area of Milo Lemert Bypass and Rock Quarry Road in Cumberland County.  Sheriff Casey Cox told CNF news that the three are considered to be armed and dangerous.   A Jeep Cherokee was found abandoned in the area of Rock Quarry road.  Cumberland County Sheriff Deputies, Crossville Police and Tennessee Highway Patrol are searching the area now.  A reverse 911 alert call has been made to a five mile radius of the search area.