Numbers 26:61

Then Nadab and Abihu, the sons of Aaron, took their respective firepans and put fire in them. Then they placed incense on it and offered strange fire before Yahweh, which He had not commanded them.

And fire came out from the presence of Yahweh and consumed them, and they died before Yahweh.

The Levites, however, were not numbered among them by their fathers’ tribe.

The Levites, however, were not numbered among the sons of Israel, just as Yahweh had commanded Moses.

But Nadab and Abihu died before Yahweh when they offered strange fire before Yahweh in the wilderness of Sinai; and they had no children. So Eleazar and Ithamar ministered as priests in the lifetime of their father Aaron.