If it is a severe laceration go to the ER, and see if you need stitch's ... or use a Band Aid (masking tape or duct tape, with a tiny piece of TP or paper towel shoved into the cut will do, if you are in a pinch)
Look for assets by Jeff Morris, sorry I can't remember his user name) on the DLS. He did a bunch of stuff for the NCYTA including elevated bridges and other EL and subway related stuff.