Ребята is used only in the plural and especially (though not always) in second-person "vocative" constructions -- thus, it's extremely close to English "Hey, you guys!"
Throbert, the word Ребята can have the substitute of "sons"?
I thank you so much for your effort Throbert, I knew from the start this translation, although short, would not be easy to assert. Indeed, it is a powerful epitaph in honour of 9 russian hikers who lost their lives in a very mysterious way back in February of 1959. Once again, thank you for your big help.