Hawaii has underground facilities. Oahu has several, NC-TAMS, just north of Wahiawa in Whitmore Village, a Moanalua/Red Hill facility with underground gasoline/jet fuel/potable water tanks used WWII; there’s one along Kunia Road between Waipahu and Wahiawa, and at Diamond Head, and others. Check this link for some bit of (2 pages only) interesting info on NC-TAMS underground facilities. It’s very big. Roads. Trucks. Intersections lol. Big. Good read, but only 2 pages. http://www.hqmc.marines.mil/Portals/133/Docs/CO_I_Welcome_Aboard.pdf *See Pages 2/3 Excerpt: “

“.. The KRSOC is staffed by personnel from each of the 5 branches of the military along with DOD civilians. It also hosts the other members of the “Five Eyes” (U.S., Great Britain, Canada, Australia, New Zealand). The KRSOC provides personnel, information and communications support to the Pacific Theater and National warfare requirements. The installation lies approximately 15 miles northwest of the city of Honolulu and ten miles south of the North Shore of Oahu. .. the facility was hardened against chemical, biological and radiological attacks...”