Commandos 3 - HD Remaster

Throwing a grenade at the below marked area in Normandy mission 1 : Cripple Nazi Support should do it. Might have to repeat it in case all 5 barrels do not explode, so would be a good idea to quick save just before lobbing the grenade.

You can start the mission on rookie difficulty and sprint with the sapper within grande range of the below area and throw it.