וַתֵּ֥צֵא אֵ֛שׁ מִלִּפְנֵ֥י יְהוָ֖ה וַתֹּ֣אכַל אוֹתָ֑ם וַיָּמֻ֖תוּ לִפְנֵ֥י יְהוָֽה׃
And there came forth fire from before the LORD, and devoured them, and they died before the LORD.
Read kabbalistic (mystical) interpretation of Leviticus 10:2: and classical mystical sources.