あのときは命からがらじゃった。
It was life and death that time.
I think I've translated the feeling of the sentence correctly but I can't fully understand the grammar.
First, I'm assuming じゃった is just old man speech for だった (it fits the character).
My main problem is that 命からがら, or just からがら, is adverbial, and there is no verb. I would expect to see 命からがら in a phrase like 命からがら逃げた ("I barely escaped with my life"), which has a verb.
This means that either I'm wrong about じゃった, or 命からがら can act as a noun, or there's something else I'm missing.