Re: I'm not sure about the key stuck to the phone at the end?
In theory ammonium nitrate is an oxidizing agent and not an explosive in its own right, although very large quantities (many tons) can detonate.
As the residents of Beirut found out one sunny afternoon not too long ago.
A fairly similar chemical, ammonium perchlorate, caused Pepcon to go boom; in both cases the stuff did not ignite by itself but by a minor fire nearby.