Carl perched high on the building's ledge and contemplated the city far below. Flashing headlights and twinkling street lamps made the filthy streets gleam with the bright promise of hope. But Carl knew. He'd been in those alleys, in the gutters infested with disease and slick with the slime of the city. Somewhere below, a woman was being mugged at knife point. A man was being gunned down on the sidewalk. A prisoner was being tortured, a shop was being looted, a car was being torched. Underneath its sparkling veneer, the city was filthy with crime.
The police were useless. Most were deep in the kingpin's pockets, the rest were deep in the bottle. To clean the streets, it would take the courage and determination of the entire citizenry. The people were desperate for hope, they'd rally behind a strong force of good. A symbol of hope with the strength to stand up to the enemies of peace who scarred the city streets night after night. Given half a chance, Carl would be that symbol.
But Carl wasn't Batman. Carl was just a fish. And fish cannot breathe on the tops of buildings.
That's how Carl died.