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[1952] AC 180 (HL). The claimant window cleaner was injured when he fell from a window ledge while cleaning upper-storey windows. He had been standing on the ledge outside the building, a practice that was obviously dangerous, but widely followed. He sued his employers for breach of their duty to provide a safe system of work (see employers liability). In general, employers do not have a duty to protect employees from their own carelessness; nevertheless in this case the employers were aware that their employees were taking risks of this kind, and should have taken steps to instruct them in a safe way to carry out their duties.