Mashable SEA reported a local recorded the whole thing and authorities initially were dumbfounded by the whole situation.
Many reports emerged blaming various factors for the incident such as rainfall and heavy wind and also the prevalence of acid in the rain.
Most likely caused by pesticide poisoning
It was later revealed that the actual cause of the incident was due to the use of pesticides in a nearby village which had caused heavy poisoning to the birds.
"Our suspicion is that the community nearby used non-natural pesticides, which poisoned them," said a spokesperson from Bali's Natural Resources Consevation Center (BKSDA).
He added that there’s a possibility that the birds have been looking for food in a massive group and have found the newly grown rice crops which had been sprayed with the pesticides to feed on.
"That's our current guess, and we've asked our partners in the field to educate the people on the use of pesticides in an effort to be mindful of other wild creatures around the area – not only the birds, but other animals as well," he added.
That's so terrible! We hope that this incident helped create some awareness on pesticides and its effects at least.