I wish I had Sycamore trees. We had a plum tree and two pines in the backyard when we moved in - but a school employee oversprayed with a weed killer and did them in, along with my strawberries, and our new Pacific Madrone.
We think the district is at it again this year. Our Seattle Sentinel Maple is just about 15' and then started dying from the top down and having leaves wither and die.
I've given up on having any trees other than dwarf fruit trees that are below the height of the fence back there.
OMG! I'd have to injure someone if they killed our trees. So sorry you have to deal with that.
We have huge pear trees out here that are over 100 years old and still produce fruit, and many of our Sycamore trees are giants, I love them.