What does 1 Samuel 6:19 mean?

But God struck down some of the people of Beth Shemesh because they looked inside the chest of the Lord. Seventy men died. The people mourned because the Lord had struck them with such a heavy blow. 1 Samuel 6:19 - Modern Text Bible

(Some people treated the Ark carelessly, looking inside when they shouldn't have, and God punished them, showing how serious it is to respect what is holy.)