Numbers 26:10 in the King James Version
And the earth opened her mouth, and swallowed them up together with Korah, when that company died, what time the fire devoured two hundred and fifty men: and they became a sign.
Context
9 The sons of Eliab: Nemuel, Dathan, and Abiram. These are that Dathan and Abiram who were called by the congregation, who rebelled against Moses and against Aaron in the company of Korah when they rebelled against the LORD;
10 and the earth opened its mouth, and swallowed them up together with Korah when that company died; at the time the fire devoured two hundred fifty men, and they became a sign.
11 Notwithstanding, the sons of Korah didn’t die.