▁two - story ▁ 3 0 6   ft ▁long ▁building ▁contained ▁a ▁cl othing ▁factory , ▁dry ▁clean ing ▁plant , ▁furn iture ▁plant , ▁br ush ▁factory , ▁and ▁an ▁office , ▁where ▁prisoners ▁of ▁the ▁federal ▁pen it enti ary ▁could ▁work ▁for ▁money . ▁They ▁made ▁items ▁such ▁as ▁glo ves , ▁furn iture ▁m ats , ▁and ▁army ▁uniform s . ▁The ▁la und ry ▁room ▁occupied ▁the ▁entire ▁upper ▁floor , ▁the ▁largest ▁in ▁San ▁Francisco ▁at ▁the ▁time . ▁Each ▁window ▁has ▁ 9 ▁pan es ▁and ▁there ▁are ▁ 1 7 ▁b ays ▁on ▁each ▁floor ▁on ▁either ▁side . ▁ ▁In ▁recent ▁years ▁the ▁building ▁has ▁been ▁updated ▁to ▁address ▁the ▁er os ion ▁of ▁the ▁concrete ▁and ▁rust ▁had ▁caused , ▁strength en ▁the ▁walls ▁and ▁flo ors , ▁repair ing ▁the ▁roof ▁and ▁adding ▁weather proof ed ▁windows ▁and ▁door ▁open ings . ▁The ▁Guard ▁Tower ▁on ▁the ▁top ▁of ▁the ▁building ▁was ▁also ▁renov ated ▁and ▁rem ount ed . ▁ ▁Leg ends ▁ ▁Psych ic ▁Da ena ▁Sm ol ler ▁and ▁psych ologist ▁Larry ▁Mont z ▁investig ated ▁the ▁prison ▁and ▁found ▁nothing ▁in ▁D - Block ▁or ▁the ▁cell house ▁but ▁equ ipped ▁with ▁a ▁magnet ometer , ▁they ▁picked ▁up ▁a ▁reading ▁in ▁the ▁New ▁Indust ries ▁Building ▁in ▁the ▁area ▁where ▁in m ates ▁had ▁been ▁employed ▁in ▁se wing . ▁Sm ol ler ▁says ▁that ▁she ▁picked ▁up ▁on ▁the ▁inten se ▁sound ▁of ▁bu zz