© National Park Service via AP
This photo released by US National Park Service shows, from left to right: Gary Favela, Don Teichner, Muku Reynolds, Steve Arthur, Linda Arthur, Robin Brum, and Mark MacKenzie. The hikers, six from California and one from Nevada, died when fast-moving floodwaters rushed through a narrow park canyon in Zion Park, southern Utah on Monday, Sept. 14, 2015.
Monday's flash flooding was
the most deadly weather disaster to ever occur in Utah. Twelve people are confirmed dead and a child is still missing after flash flooding in Hildale, and another six are confirmed dead with another individual missing after flooding in Zion National Park.
Prior to Monday, that dubious distinction would have fallen to
a pair of avalanches in Alta in 1881 and 1885. In each case, 15 people were killed.
The most deadly flooding in Utah happened in 1923 in Farmington and in 1965 in Sheep Creek Canyon near Flaming Gorge.
Utah has also experienced days where more people died in a sudden, violent events. The worst single day's disaster happened in the town of Scofield.
Comment: Here's a possibility of what it was.