Yikes! They're still cleaning up the mess!
https://www.stgeorgeutah.com/news/archive/2021/06/29/cdr-worst-ive-ever-seen-flash-flood-spreads-mud-through-springdale-closes-zion/#.YNy9nS-cZN0
https://www.sltrib.com/news/2021/06/29/flash-flooding-closes/
Anyone traveling to that area, the park website cautions that they "will be in modified operations on Wednesday, June 30 due to clean-up activities. Motorists should exercise caution. Visitors should expect traffic delays, debris on roads, and potential closures of trails and parking areas."
https://www.nps.gov/zion/learn/news/zion-national-park-continues-clean-up-after-flash-flood.htm
Some of the photos are good examples of why one should NEVER hike the Narrows or any other slot canyon with rain in the forecast upstream. And never park in or very near a wash!