The accident took place on Sunday when an old, overcrowded truck that was contracted by wedding guests fell off the Gelan Bridge, where villagers said traffic crashes have happened before.
The medical director at Bona General Hospital in the southern Sidama region, Lemma Lagide, told The Associated Press on Monday that 64 people died on site and two others at the hospital.
He said those patients in need of more sophisticated critical care were transferred to a bigger hospital in Hawassa.
Delays in rescue efforts in the remote village were blamed for the high number of casualties. Villagers said they tried to save people from the raging river only with sticks.
A villager, Serak Boko, told AP that moments before the accident, music was blasting out of the truck and people dressed in suits were dancing and waving.
It is common for people in rural Ethiopia to hire trucks instead of buses to transport them to social events like weddings because they are more affordable and carry many people. Most of those on the truck were men because they are culturally required to escort the bride from her home to the groom's house.
"The area always has regular accidents around the river as it is poorly constructed," said resident Fasil Atara, referring to the road lacking bumps and warnings.
With desolate infrastructure and overcrowded public transportation, Ethiopia has had similar accidents in the past. In August, 38 people died after a bus rolled over in Amhara region.
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