yep that does the trick for me...
the only thing that sucks is that you hear the objects getting destroyed (that annoying breaking fence sound ;D) as soon as the mission starts.
So maybe you could have one explosion go off somewhere in the distance that is to "blow the town's transformer" and thus take the power out
I was fooling around with a mission sort of like this and I had one team that was supposed to go and take out the power grid while I waited at the edge of town. Then the explosion happened that I had set up and I got to watch all the lights go out in the town via setdammage... It worked
like a charm
Incidentally... did you know that all objects are assigned ID numbers consecutively?
so object 1 is literally the first object placed on a map and if you can find the highest ID number on an island that will tell you approximately how many total objects it contains
Just a little useless OFP trivia... lol ;D