The most gut - wrenching part of the AMA comes when two teen neighbors who had just joined the Army were sent closer to the site of the explosion: (businessinsider.com)
«When a thermonuclear weapon is surrounded with with ordinary cobalt (cobalt - 59) metal,» as Russia's Status 6 is rumored to be, «the fast neutrons escaping the explosion will instantly transmute it into radioactive cobalt - 60, which would vaporize, condense, and then fall back to earth tens, hundreds, or thousands of miles from the site of the explosion.» (businessinsider.com)
They cited the recovery of three propane canisters at the site of the explosion. (fortune.com)