The Ecuadorian Ministry of Atmosphere said it was due to "natural erosion".
"The crumple of Darwin's Arch, the eye-catching all-natural bridge found significantly less than a kilometre from the main location of Darwin Island, was reported," the ministry said.
The formation, labeled in honor of the British biologist Charles Darwin, is considered a major scuba diving place.
"Darwin's Arch is created of natural rock that at one particular time would happen to be a part of Darwin Isle, which is not available for trips by land."
Scuba divers on a vacation on board one of many liveaboard departures aboard the Galapagos Agresssor III, which delivers serviced diving cruise departures, suggested in a post shared on Facebook that one of its trip groups witnessed the episode take place.
"The fact is that currently, our visitors on the Galapagos Aggressor III experienced a once in a life time event," the corporation shared.
"This morning at 11:20 a.m. local time, the world popular Darwin's Arch collapsed before their sight.
"Some within the scuba & vacation industry happen to be speaking about this now as 'The Pillars of Evolution'. We are going to miss this iconic site."