REALLY WOULD LIKE SOME HELP HERE

[Majortom]

Hello all

I am playing SS3: TLS
American campaign and have run across a timer that's set at 277:46:00 ..
there are three enemy left: a soldier , bison and stug . if I kill anyone of them I get a timer and the town gets bombed.
can anyone please help with this..i cant get non of the much needed ammo from town . on a post someone said it was a timer bug that a timer had to be changed in an xml file but I don't know witch on or even what the timer would be called.