Stuck on The Sheltering Night - The Bridge!

[mccormack.d]

How the heck do you blow up the bridge in the single mission, The Sheltering Night, for MOW: Vietnam - Special Edition?? I managed to sneak all 4 of my men through the entire map without setting off the alarm or losing one of my men just to get to the bridge and not be able to blow it up!!! I've tried setting charges individually in the spot that the binoculars show in the mission objectives. I've tried setting charges in pairs and as an entire squad (all 4 of my men). The charges blow and nothing happens to the bridge!!! The vehicles just keep rolling over it! PLEASE HELP!!!