As the tribe moved north they faced little difficulty, but once they reached Fort Cobb, Oklahoma disaster struck. Wichita Agency agents housed the Tonkawa along the Washita River, and that night, October 23rd, 1862,
a small army of Shawnees, Delawares, Kickapoos, Caddos, Comanches, and Kiowas attacked the Tonkawa settlement near the Whasita River, killing 137 women, men and children, more than half the tribe.
The Attack itself also took the lives every member of the Wichita Agency present when the attackers sacked the fort to prevent them from aiding the Tonkawa. Among the dead was Chief Can't-Kill-Him and the rest of Tonkawa leadership.
After the attack the Tonkawa survivors fled south to Fort Griffith, Texas where they remained for the next twenty years. The attack on the Tonkawa was politically motivated. The Tonkawa had acted as scouts for the Confederacy, and before American soldiers against the Comanche and Shawnee Tribes. Additionally, the belief that the Tonkawa were cannibals increased the natives vehement hatred of the tribe and spurred them on to slaughter even the women and children. in 1877, the was a push among anthropologists to study Tonkawa culture and aid the survivors of the massacre, as few members of the tribe remained and it looked like the people would die out. In 1886 they were returned to Oklahoma and moved to Fort Oakland, which in 1894 was renamed to Tonkawa, Oklahoma. The majority of the tribe still live in this area.
By 1930 there were only 86 Tonkawa left, and the tribe looked doomed to extinction. After WWII, Tonkawa fortunes turned and the tribe as grown to double the pre-massacre numbers by The Seventies, and close to 1000 today.