On 13 May 2021, a number of wild Asiatic elephants Elephas maximus in Bamuni Reserve Forest, Nagaon District, Assam, India, were reported dead. Large herds of elephants frequently traverse one of two corridors originating from Kaziranga National Park: (1) south-westwards to Doboka, via Swang Reserve Forest, and (2) southwards to North Karbi Anglong Wildlife Sanctuary. Local people discovered the dead elephants in the Bamuni Hills and, as we were nearby working in these corridors, we visited the location, where we observed 18 dead elephants on a hilltop: five males, and 13 females, of which four were juveniles. The area had received incessant rain for several days preceding the incident, along with heavy thunderstorms and lightning. Local people suggested lightning as the possible cause of the deaths. On 14 May, forest officials of the Assam government visited to gather evidence, assisted by veterinary officials who conducted post-mortems. Preliminary reports, based on evidence of burns on the trunks and fur of two of the elephants, along with a few burnt teak trees, support the hypothesis that the deaths were a result of lightning.

Although the cause of these deaths has not yet been definitively determined, the simultaneous deaths of a number of animals in a single location has occurred elsewhere. In 2016, 323 reindeer were killed by lightning in the Hardangervidda National Park, Norway (theverge.com/2016/8/29/12690402/lightning-strike-kills-norway-reindeer-death-why-science). Lightning can strike an animal directly from above or indirectly through tall trees via side flashes. When lightning strikes an animal directly, or the ground nearby, the energy can subsequently spread along the ground by up to 80 m, subjecting any other animal within this range to an electric shock. In the case of a side flash, lightning strikes an animal's body sideways from a tree hit directly. Fatalities from side flashes are fewer than from direct hits.