Dist. Ct. erred in granting defendant-railroad’s motion for summary judgment in plaintiff’s FELA action seeking damages when top rail of chain-link fence that plaintiff was installing fell and struck plaintiff on his neck and shoulder. While Dist. Ct. believed that plaintiff could not establish causation element of negligence claim since plaintiff did not produce expert testimony as to why rail fell on plaintiff, Ct. of Appeals found that there was sufficient evidence of causation to defeat instant summary judgment motion where record contained evidence that rail fell of its post because it was either too short or was improperly tightened. Moreover, Dist. Ct. erred in requiring that plaintiff produce direct evidence of causation and to exclude other possible causes for why rail dislodged from its post since circumstantial evidence alone could support jury verdict under FELA, where, as here, matter is within realm of lay understanding and common knowledge.