Numbers 26:9-10

9The sons of Eliab were Nemuel, Dathan, and Abiram. These are the Dathan and Abiram, representatives of the congregation, who contended against Moses and Aaron in the company of Korah, when they contended against the Lord;

10and the earth opened its mouth and swallowed them up together with Korah when that company died, when the fire devoured two hundred and fifty men; and they became a sign.