A large waterfall natural bridge was suddenly created on February 2, 2020, by the collapse of a sinkhole behind the San Rafael Waterfall, which had previously been the largest waterfall in Ecuador. The new natural bridge is NABSQNO 18M-212655-9988525.
Our analysis of Google Earth and other images seems to indicate that the resulting natural arch is possibly the longest in the world, perhaps exceeding 400-foot Fairy Bridge in China. It will be interesting also to see if this bridge lasts more than a few years.
[UPDATE: THE BRIDGE COLLAPSED AFTER ONLY ONE YEAR! See comments below.]
The Ecuador Ministry of Environment announced that it is carrying out studies to determine what happened. Some question has been raised if the event was totally of natural origin, perhaps aggravated by being in a volcanic and earthquake activity zone, or if it may have been exacerbated by the construction of a nearby hydroelectric dam which removes sediment from the river, making it more erosive. The International Union for the Conservation of Nature (IUCN) is set to hold an academic debate to find stronger scientific ground to determine what happened.
BEFORE (image credit, NASA):
AFTER (image credit, Ecuador Ministry of Environment):
The 3-minute video below shows both before and after images. The new natural bridge is visible in the still image below and at 1:37-1:42 and 2:15-2:36. Beginning around 2:26 you can see a significant amount of water flowing out of the left abutment. This does not bode well for the longevity of the arch.