What film is this? French bank heist flick...
Spoiler alert as I give away some of the plot here:
I suppose I could just google it but picking DU's collective brain is so much more fun. I believe it's a french film. It's one of the better bank heist gone wrong films I've seen. It's pretty violent. The main character is a skinny guy that is brought in by the professionals as a side man on the job. Getting into the vault itself involves rigging up some explosives which is handled by their nerdy explosives guy. Once they are in though they discover that the real money is behind a wall with a small barred window. On the other side of the window is a security guard. There is a gruesome scene in which they toss explosives through the small window and blow down the wall.
= new reply since forum marked as read
Sounds about right, but I can't remember all the details. I remember I enjoyed it though.
and then completely forgot about it. But since you mentioned it I might look it up some time. My kind of movie. 
