Actually you did very well. You have good tonal range and detail, even i the shadows. THe sky is very well done. Compositionally not my favorite. The dark under-pier is a bit oppresive. Frome a B&W techique standpoint you there!
I agree with the above comment. Being under the bridge alters the mood toward the dark - I'd strive for a touch more balance, but I think the b&w works well. The only technical flaw I see is the haloing (white line) where the bridge meets the sky.
I like the strong graphic nature of your shot. Very eye-catching. Your B&W image looks quite good. I always looks for a full range of tones from near white (with texture) to near black (with shadows) if that's possible in a shot. You've got that level of processing in this image. Very nice shot.