good feedbacks and answer. thank you 
i thought that the Missile wasn’t launched due to the operator (the person who control the launch) may have been bitten by the zombie so when the person tries to launch the rocket, the infection kicks in and turn him/her into zombies. leaving the rocket active but yet not launched.
for the missile type, if its a nuclear type missile, the crater seems too small for a nuclear missile but the severe radiation and damage leave behind is good (although somehow it didn’t damage living creatures like fungal bloom)
for random crater, some of the random crater player can found is somehow not too severe and located around road and some building, the size of the crater itself is small, meaning it must be some kind of ballistic tactical missile for something… (if its nuclear missile, the crater should be much bigger)
i don’t know if its rare or common, but 75% of my gameplay session is guaranteed to have missile silo near a city/ refugee camp.