A coroner has called for extra signage at a Waitākere Ranges waterfall after two teenagers were killed in a flash flood in 2018, Stuff reports. Mitch Woolley​ and Sosiveta (Sosi) Turagaiviu, both 17 years old, were swept away while trying to cross a swollen river near Cascade Falls in the West Auckland ranges during heavy rainfall. But Katherine Greig said there were no signs warning about the dangers associated with heavy rainfall in the area.