Alphonso Burke (plaintiff) was using a machine made by Spartanics, Ltd. (defendant) while working for Metal Etching Company (defendant). Metal Etching had modified the Spartanics machine. The effect of the modification led to employees regularly—and unsafely—placing their hands on a cutting surface. Burke had been using the machine in that unsafe manner for eight months. While working with his supervisor, Burke placed his hand on the cutting surface. The supervisor, unaware of the location of Burke’s hand, activated the machine. The machine severed several of Burke’s fingers. On the front of the machine, there was a warning about touching the cutting surface, but on the back of the machine, where Burke was located, there was no warning. Burke sued Spartanics, alleging a breach of the duty to warn. Spartanics impleaded Metal Etching as a third-party defendant. The jury instructions, over Burke’s objection, stated that there was no duty to warn if Burke knew of the danger or if the danger were generally known. The jury returned a verdict against Burke. Burke appealed.