Jeffrey DiPalma was working for a company that had been hired to rehabilitate several bridges in Buffalo.  One day, while standing on a platform, DiPalma was shoveling concrete debris into an unsecured skid box that had been placed on a forklift.  DiPalma put a load of debris in the box and turned to scoop up another when the box slid, fell approximately 1 to 2 feet and hit him on the back.  The Fourth Department held that the strict liability provisions of Labor Law §240 applied even though there was no significant height difference between the skid box and the platform that DiPalma was standing on.  The court noted that because of the weight of the skid box, its contents and the potential harm that it could cause, it could not say that the elevation difference was de minimus.

http://www.nycourts.gov/courts/ad4/clerk/decisions/2011/12-30-11/pdf/1369.pdf