s ▁and ▁col lapsed ▁walls . ▁R ough ly ▁thirty ▁separate ▁vehicles ▁were ▁destroyed ▁in ▁the ▁bl ast . ▁ ▁The ▁nearest ▁fire ▁station ▁was ▁just ▁six ▁blocks ▁away . ▁Fire fig h ters ▁were ▁initially ▁alert ed ▁by ▁the ▁force ▁of ▁the ▁explos ion ▁bu ck ling ▁the ▁fire ▁station ▁door . ▁Origin ally ▁it ▁was ▁thought ▁that ▁a ▁car ▁had ▁struck ▁the ▁fire ▁station , ▁but ▁when ▁fire fig h ters ▁went ▁outside , ▁they ▁quickly ▁realized ▁this ▁was ▁not ▁the ▁case . ▁One ▁of ▁the ▁drivers ▁soon ▁sp otted ▁smoke ▁and ▁a ▁fire ▁engine ▁and ▁a ▁param edic ▁unit ▁were ▁dispatch ed ▁to ▁go ▁to ▁this ▁smoke . ▁These ▁vehicles ▁were ▁the ▁first ▁res cu ers ▁on ▁the ▁scene ▁and ▁arrived ▁just ▁three ▁minutes , ▁forty ▁seconds ▁after ▁the ▁initial ▁explos ion . ▁They ▁immediately ▁sent ▁for ▁the ▁department ' s ▁heavy ▁urban ▁rescue ▁team . ▁Ult imately , ▁ 1 2 5 ▁fire fig h ters ▁in ▁ 3 4 ▁vehicles , ▁ 5 2 ▁police ▁officers , ▁multiple ▁private ▁amb ul ances ▁and ▁the ▁American ▁Red ▁Cross ▁all ▁helped ▁at ▁the ▁scene , ▁which ▁was ▁class ed ▁by ▁the ▁fire ▁service ▁as ▁a ▁five - al arm ▁emer gency . ▁ ▁Investig ation ▁A ▁full ▁investigation ▁was ▁launched ▁into ▁the ▁accident ▁by ▁several ▁government ▁ag encies , ▁as ▁well ▁as ▁legal ▁represent atives ▁for ▁the ▁families ▁of ▁the ▁dece ased . ▁The ▁investigation ▁determined ▁that ▁the ▁leak ▁was ▁initially ▁discovered ▁by ▁employees ▁of ▁the ▁contract or ▁J .