On September 11, 1916, a hotel worker named Red Eldridge was hired as an assistant elephant trainer by the circus. On the evening of September 12 he was killed by Mary the elephant in Kingsport, Tennessee, while taking her to a nearby pond to splash and drink. There have been several accounts of his death. One, recounted by W.H. Coleman who claimed to be a witness, is that he prodded her behind the ear with a hook after she reached down to nibble on a watermelon rind. She went into a rage, snatched Eldridge with her trunk, threw him against a drink stand and stepped on his head, crushing it. A contemporary newspaper account, from the Johnson City Staff, said that Mary "collided its trunk vice-like about [Eldridge's] body, lifted him 10 feet in the air, then dashed him with fury to the ground... and with the full force of her beastly fury is said to have sunk her giant tusks entirely through his body. The animal then trampled the dying form of Eldridge as if seeking a murderous triumph, then with a sudden... swing of her massive foot hurled his body into the crowd."
The details of the aftermath are confused in a maze of sensationalist newspaper stories and folklore. Most accounts indicate that she calmed down afterward and didn't charge the onlookers, who began chanting, "Kill the elephant!" Within minutes, local blacksmith Hench Cox tried to kill Mary, firing five rounds with little effect. Meanwhile, the leaders of several nearby towns threatened not to allow the circus to visit if Mary was included. The circus owner, Charlie Sparks, reluctantly decided that the only way to quickly resolve the potentially ruinous situation was to kill the elephant in public. On the following day, a foggy and rainy September 13, 1916, she was transported by rail to Erwin, Tennessee, where a crowd of over 2,500 people (including most of the town's children) assembled in the Clinchfield Railroad yard.
The elephant was hanged by the neck from a railcar-mounted industrial crane. The first attempt resulted in a snapped chain, causing Mary to fall and break her hip as dozens of children fled in terror. The severely wounded elephant died during a second attempt and was buried beside the tracks. Although the authenticity of a widely distributed (and heavily retouched) photo of her death was disputed years later by Argosy magazine, other photographs taken during the incident confirm its provenance.