A design engineering expert witness advises on a case involving a pool filter explosion that caused severe brain injury to the plaintiff in Missouri. The plaintiff was tasked with replacing the pool filter. The filter is made up of two central pieces and wrapped with a metal band to keep it stable as it is normally pressurized. The plaintiff flipped the switch to depressurize the system, undid the band and put a new filter in. The plaintiff tightened the band back up and energized the filter system. The canister started to leak so the plaintiff went to tighten the band and, in the process, the top of the filter system blew up and struck the plaintiff’s head. The plaintiff now suffers from traumatic brain injury and has no recollection of the event. The homeowner and the servicing agent disposed of the offending product before the unit could be inspected. The plaintiff seeks an expert in pool filter systems to conduct an analysis of the documentation the plaintiff currently has alleging defective design of the filter and that there are safer alternatives.