There's also the bit where said blameless girl...maninahat said:I'm going to go with Akira. Sure, there are more gory or violent anime, like Elfen Lied, but the OP asked for "brutal". The violence in Akira is brutal. The most innocent or undeserving characters are victims to most unpleasant and visceral suffering. Elfen Lied opens with exploding heads and gratuitous fan service, so it feels like a childish cartoon. Akira has a character step on a piece of glass with his bare foot, or a blameless girl getting her nose punched in - and it looks ten times worse.
...gets horrifically crushed. You hear her scream in agony (which is still one of the most blood curdling screams I've ever heard) and see her eyes bug out as she's slowly smushed.
What makes it even worse is that, as you said, she's the only character in the movie who's completely innocent. She only tried to help.