Tails.
Seriously.
How the forget am I to give my opinion if from what I gathered from the second paragraph is that blowing the bridge makes everyone happy and not blowing it means an escaped van, an undestroyed barge, and a nightmare waiting to happen?
It's really not that hard to understand.
Your orders are apparently to blow up the bridge when a specific national socialist van attempts to cross it. You see the van, but you also see a barge carrying innocents (these being the prisoners), which is going under the bridge.
If you blow the bridge, you follow orders but you also kill all of the innocents on the barge.
If you don't blow the bridge, you disobey orders. The van you were supposed to take down with the bridge will have escaped, but the innocents will live another day.