And Nadab and Abihu died before the LORD, when they offered strange fire before the LORD, in the wilderness of Sinai, and they had no children: and Eleazar and Ithamar ministered in the priest’s office in the sight of Aaron their father.
Nadab and Abihu passed away while offering unusual fire to God in the Sinai desert. They didn't have kids. Eleazar and Ithamar took over as priests, observed by their dad, Aaron.