▁by ▁profession ▁and ▁the ▁camp ▁construction ▁expert ▁in ▁the ▁SS . ▁Work ▁had ▁comm enced ▁in ▁early ▁November ▁ 1 9 4 1 , ▁using ▁local ▁build ers ▁over seen ▁by ▁a ▁squad ▁of ▁Tra wn iki ▁gu ards . ▁The ▁installation , ▁res emb ling ▁a ▁railway ▁trans it ▁point ▁for ▁the ▁purpose ▁of ▁forced ▁labour , ▁was ▁finished ▁before ▁Christmas . ▁It ▁featured ▁ins ulated ▁bar ra cks ▁for ▁show ering ▁among ▁several ▁other ▁structures . ▁Some ▁local ▁men ▁were ▁released . ▁The ▁SS ▁completed ▁the ▁work ▁in ▁February ▁ 1 9 4 2 ▁by ▁fitting ▁in ▁the ▁tank ▁engine ▁and ▁the ▁exhaust ▁pip ing ▁systems ▁for ▁g ass ing . ▁The ▁trial ▁kill ings ▁were ▁performed ▁in ▁early ▁March . ▁ ▁The ▁" Final ▁Solution " ▁was ▁form ulated ▁at ▁W ann see ▁in ▁late ▁January ▁ 1 9 4 2 ▁by ▁the ▁leading ▁pro ponents ▁of ▁g ass ing ▁( who ▁were ▁una ware ▁of ▁Be ł ż ec ' s ▁existence ), ▁including ▁Wilhelm ▁Dol p heid , ▁Ludwig ▁Los acker , ▁Hel mut ▁T anz mann ▁and ▁Governor ▁Otto ▁W äch ter . ▁Dol p heid ▁negoti ated ▁with ▁the ▁SS - O ber führ er ▁Vik tor ▁Bra ck ▁in ▁Berlin ▁for ▁the ▁use ▁of ▁the ▁A ktion ▁T 4 ▁personnel ▁in ▁the ▁process . ▁Only ▁two ▁months ▁later , ▁on ▁ 1 7 ▁March ▁ 1 9 4 2 , ▁the ▁daily ▁g ass ing ▁operations ▁at ▁Be ł ż ec ▁ex termin ation ▁camp