Did God burn to death all of Korah's children? Bible Contradictions

This Bible contradiction is from the Skeptic's Annotated Bible.

Verses

Yes, God buried them alive.

Numbers 16:27-33 View context

So they gat up from the tabernacle of Korah, Dathan, and Abiram, on every side: and Dathan and Abiram came out, and stood in the door of their tents, and their wives, and their sons, and their little children.

And Moses said, Hereby ye shall know that the LORD hath sent me to do all these works; for [I have] not [done them] of mine own mind.

If these men die the common death of all men, or if they be visited after the visitation of all men; [then] the LORD hath not sent me.

But if the LORD make a new thing, and the earth open her mouth, and swallow them up, with all that [appertain] unto them, and they go down quick into the pit; then ye shall understand that these men have provoked the LORD.

And it came to pass, as he had made an end of speaking all these words, that the ground clave asunder that [was] under them:

And the earth opened her mouth, and swallowed them up, and their houses, and all the men that [appertained] unto Korah, and all [their] goods.

They, and all that [appertained] to them, went down alive into the pit, and the earth closed upon them: and they perished from among the congregation.