A woman on one of Taiwan's toughest mountain trails was killed by a sudden flash flood, a warning for anyone heading into the mountains during the rainy season.

• A hiker was swept away while crossing a river valley in Yushan National Park after heavy mountain rain made the stream rise fast.
• Her three companions were left stranded and radioed for help; rescuers reached them the same night.
• A 26-person search team of firefighters, rangers, police and volunteers used a drone to find her body the next afternoon.
• No typhoon warning was in place, but more than 300 millimeters of rain fell in the area.
• Local officials did not know the group was there because they entered from a neighboring county, and are now urging hikers to file their plans and check the weather.

Outlook: With a sea warning for Typhoon Saudel expected within days, more rain and further mountain rescue risk are likely in eastern Taiwan.