"There’s nothing wrong with having a happy life"

[Kumirei]

幸い context sentence help

Context sentence: 幸い命に別状はありませんでした。 There’s nothing wrong with having a happy life. 幸い is listed as a noun and na-adjective meaning happiness, luck, fortune. As an adverb it means luckily, fortunately​. So in the context sentence I’m confused about 幸い being right before 命 and resulting in the translation “happy life”. As a noun shouldn’t it be 幸いの命? Or as a na-adjective shouldn’t it be 幸いな命? And I don’t see how it could be modifying the noun 命 as an adverb given the meaning of 命 (if you can…