(Salem, OR)  --  Officials say some Salem residents have been staying away from home throughout the night because of a liquid-oxygen leak.  The leak, located in the 46-hundred block of Windsor Way Northeast, prompted the evacuation last night of homes and businesses within a six-block radius.  The leak was contained by about 8:40 last night, but the evacuation remained in place.  There's been no word on what caused the leak.