"There are no children by the deep water."

Translation: A mély víznél nincsenek gyerekek.

[Feren6Girl]

I have it where Duolingo gives you three pre-printed answers to choose from, and the correct one is:
"A mély víznél nincsenek gyermekek."
In this context, what is "gyermekek"?

[guirita123]

Can anyone please explain why this sentence construction is incorrect? A mély viznel gyerekek nincsenek.

[vvsey]

It is not incorrect, maybe slightly unusual but othewise good.