jakarta indonesian authorities detain fireworks factory owner manager suspicion negligence explosions fire rip warehouse outskirts jakarta kill 48 workers injure dozens police say saturday blaze manufacture hub tangerang one bad industrial disasters hit southeast asia big economy safety standards often weakly enforce police say fire start spark weld operation light stack raw materials use make fireworks cause least two explosions could hear miles away men suspect negligence lead deaths say jakarta police spokesman argo yuwono owner pt panca buana cahaya sukses factory operations manager detain police look welder owner also suspect employ underage workers police say neither two detain available comment tangerang regent ahmed zaki say friday company operate two months permit package produce fireworks preliminary investigations witness account show 30 victims find back factory run try escape others break hole wall get police deny report front gate exit factory lock time fire body many char beyond recognition take away gutted factory family members provide dna sample try identify dozens workers admit hospital burn 80 percent body hospital officials say remain critical condition expect death toll rise indonesia detain owner deadly fireworks factory blaze