▁plant , ▁which ▁meant ▁aircraft ▁were ▁frequently ▁flying ▁over ▁the ▁building ▁at ▁low ▁alt itudes . ▁No ▁actions ▁were ▁taken . ▁ ▁In ▁the ▁late ▁evening ▁hours ▁of ▁Friday , ▁February ▁ 1 7 , ▁van ▁Ste enberg h ▁ign ited ▁the ▁final ▁round ▁of ▁dynam ite . ▁F ear ing ▁that ▁the ▁bl ast ▁might ▁have ▁set ▁off ▁an ▁alarm ▁in ▁the ▁bank , ▁he ▁fled ▁the ▁site ▁to ▁return ▁on ▁the ▁following ▁afternoon ▁and ▁ensure ▁nobody ▁appeared ▁to ▁have ▁grown ▁susp icious . ▁The ▁bl ast ▁had ▁indeed ▁been ▁heard ▁by ▁two ▁local ▁residents , ▁who ▁had ▁thought ▁it ▁to ▁be ▁the ▁son ic ▁bo om ▁of ▁a ▁f ighter ▁jet . ▁Van ▁Ste enberg h ▁entered ▁the ▁building ▁through ▁his ▁tunnel ▁on ▁Saturday ▁night ▁and ▁found ▁he ▁had ▁bl asted ▁a ▁ 1 4 ▁by ▁ 1 6 ▁in ch ▁( 3 5 ▁by ▁ 4 0 ▁cm ) ▁hole ▁into ▁the ▁v ault ▁floor , ▁just ▁in ▁the ▁center ▁so ▁it ▁had ▁not ▁set ▁off ▁the ▁burg lar ▁alarm ▁and ▁had ▁also ▁missed ▁heavy ▁steel ▁rein for cing ▁bars . ▁Author ities ▁believed ▁van ▁Ste enberg h ▁had ▁used ▁magnetic ▁loc ators ▁to ▁determine ▁the ▁best ▁location , ▁which ▁he ▁denied , ▁stating ▁he ▁had ▁been ▁“ just ▁luck y ”. ▁Van ▁Ste enberg h ▁lo oted ▁$ 4 5 , 6 8 9 . 5 3 ▁in ▁bank ▁notes ▁and ▁co ins , ▁of ▁a ▁total ▁of ▁$ 1 5 0 , 0 0 0 ▁kept ▁in ▁the