A barge carrying 600 gallons of diesel fuel sank in waters off the Galápagos Islands early Sunday, prompting an emergency cleanup effort in the environmentally sensitive area, park officials said on Twitter. Video showed the barge overturn after a crane operator lost control of a container that was being loaded aboard, and the crane toppled over onto the vessel.

Ecuador's Environmental Minister Raul Ledesema Huerta tweeted Sunday that "immediate actions" were being taken to reduce the environmental risk.

Dramatic moment barge carrying 600 gallons of fuel sinks in Galapagos Islandshttps://t.co/ELaWkBSwsj pic.twitter.com/7eQuxGCwSM — BBC News (World) (@BBCWorld) December 23, 2019

Crews placed barriers and panels to try to contain the diesel fuel, according to the Galápagos Park. Officials also launched an investigation into what led to the incident.

#SanCristóbal| El @parquegalapagos y @armada_ecuador colocan barreras de contención y paños absorbentes para reducir el riesgo ambiental por hundimiento de gabarra Orca, con 600 galones de diesel almacenados. Desde #SantaCruz se dispone el envío de material de contingencia. pic.twitter.com/nQ0aRVug8I — Parque Galápagos (@parquegalapagos) December 22, 2019

SOS Galápagos, an environmental advocacy group, posted a photo of the spill and denounced the operation as "illegal and dangerous." They also warned that the oil spill would reach a beach popular with tourists.

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The 19 islands and surrounding marine reserve of the Galápagos, more than 600 miles off the coast of Ecuador, are a UNESCO World Heritage site. One of the richest ecosystems in the world, the Galápagos inspired Charles Darwin's theory of evolution by natural selection after his visit in 1835. The islands now attract more than 220,000 visitors a year, a concern for conservationists who worry about maintaining the Galápagos' unique ecosystem.