Policeandbomb disposalexpertsrushed tothe scenefoundaredplastic bagunder Beizuo. Experts and police carefullyopenthebag, there is also a box wrappedin several layers of newspaper.
Plenty of warning signs also preceded Nigerian Umar Farouq Abdulmutallab's attempt to blow up Northwest flight 253 over Detroit on Christmas Day 2009 with an underwear bomb made with PETN, a plastic explosive that was not detected by airport security.
Reid's shoes allegedly contained several bomb-related materials including the explosive PETN, plastic chemicals to gel and mold the explosives and TATP, a highly sensitive material needed to detonate the shoe bombs, sources told CNN.