From the weight it appears to be of foreign manufacture. As such there could be any amount missing worldwide, but the ludicrously small amount missing from the construction site should empower the trillion dollar anti-terrorism industry for yet a few more days.
I don't know anything about explosives. How much damage could 110lbs of Blastex do, anyhow?
The converse is not true, however. My wife buys many of her perfume-making supplies from foreign suppliers; she has to do all her purchasing in metric. Fortunately, most of that industry is converting to metric, so most of her "recipes" use grams and milliliters...
Just a guess ... I know in my neck o' th' woods there's a whole bunch of pissed of conservatives.