substance would burn, create a decompression and you would have an explosion. this is not something that would take down a facade of a building. going to be careful not to describe certain parts. >> but it could kill. >> it would probably likely kill you, perhaps me and perhaps injure everybody in here. >> so had this gone right or gone wrong and had this guy been a better -- we don't know what it is, been a better bomb maker or made mistakes, there are consequences. these 13 bombs could have killed a lot of people. >> and the director was right to point out, with explosives, i'm not totally comfortable saying what the explosive was, even if this dropped, if a mail carrier got into a car or vehicle accident, sometimes there's