Flash floods are common along Hawaii's streams. Heavy rains come suddenly and the steep cliffs funnel all the water into the gulches. The high walls along Koloa Gulch become increasingly narrow in the back, with steep walls on either side, making this an especially dangerous area during heavy rains. On Februay 12, 1994 a boyscout group was on a campout which was cut short because of heavy rains during the night. While hiking out early in the morning, Jonathan and two others were swept away in a flash flood that took Jonathan's life at the age of 11. The cache is at the memorial that was built by his friends and family a year after his death.
Koloa Gulch is a beautiful place with amazing waterfalls and I highly recommend this hike but there are dangers, as this memorial points out. Please hike with safety in mind and pay close attention to changing weather conditions. HTMC has some great info on
hiking safety.