SOLVED. YA, possibly during the depression, spoilers ahead [s]

[Katie]

I've read this book within the last ten years and would obviously like to re-read it. The main thing I remember is that there are multiple children in the family and the one boy ends up living underground. It might've been set during the great depression but I'm not certain. The main character is a girl. If I remember anything else I'll post it here.

[Rainbowheart]

What do you mean by underground? I thought of Cave Under the City, but the MC is a boy.

[Katie]

He literally ends up living either beneath the ground underneath the house or in a series of caves underneath the property.

I believe that one of the children also drown/almost drown.

[Andria]

Thursday's Child, maybe?

"Harper Flute believes that her younger brother Tin, with his uncanny ability to dig, was born to burrow. While their family struggles to survive in a bleak landscape during the Great Depression, the silent and elusive little Tin - "born on a Thursday and so fated to his wanderings" - begins to escape underground, tunneling beneath their tiny shanty."

[Katie]

Yes!!!! Thank you so much!