Fire resulting in electrical panel and all associated components being destroyed

A dry location main distribution panel was installed on an electrical pole in an outdoor location. The panel board was installed in a 3/8” plywood enclosure with roofing materials on top but with holes all around the enclosure including on the top. (See Photo #1) Water was able to infiltrate the plywood enclosure and eventually the panel board resulting in corrosion building up on the electrical connections at the internal components.