6.4 FELA-Causation is a legal concept that is used in personal injury cases involving railroad workers who are injured on the job. It is based on the Federal Employers’ Liability ActFELLLA), which is a federal law designed to provide compensation to railroad workers who are injured on the job due to negligence on the part of the railroad company or its employees. The 6.4 FELA-Causation standard requires that the railroad worker must show that the injury was the direct and proximate result of the negligence of the railroad company or its employees. There are two types of 6.4 FELA-Causation, which are “actual” and “constructive” causation. Actual causation requires that the railroad worker must prove that the injury was caused by the railroad company or its employees, while constructive causation requires that the railroad worker must prove that the railroad company or its employees created an environment or situation that was a substantial factor in causing the injury.