"The 36-floor building near the tourist mecca of Waikiki was built in 1971, before sprinklers were mandatory in high-rises. It has over 500 units"
Make it retroactively mandatory for the "large" buildings.  It will be very expensive, but I don't see an alternative.  It could have been much worse.
"In buildings protected by properly designed and maintained fire sprinklers, over 99% of fires were controlled by fire sprinklers alone"
https://en.wikipedia.org/wiki/Fire_sprinkler