Multnomah Falls Closed Indefinitely
OPB Article here: http://www.opb.org/news/article/oregon-multnomah-falls-closed-foreseeable-future/
TL/DR: Burning the moss off the rock faces destabilized the rock, leading to a danger of rockfall. Funny, but I seem to recall being taught moss on rock was a bad thing because the roots broke up the rock, leading to rockfall.
Seriously, can we stop trying to make everything 100% safe for everyone?