Disused military tunnels snake beneath the crater of Diamond Head, out of sight of the tourists lounging near the volcano on Waikiki Beach but very much on the mind of Gene Ward, a state representative from Honolulu.
Alarmed by North Korea's latest missile tests and claims that its newly developed intercontinental ballistic missile (ICBM) can carry a large nuclear warhead, Ward believes it is time to refurbish the tunnels as civilian shelters in case of a North Korean attack.
"We've had wake-up calls before but what happened on July 3 is shaking us out of bed," said Ward, referring to Pyongyang's latest missile test.