sugar maple tree looks bad

my sugar maple tree is approx.10 years old... it leafed out normally(leaves seem small though) this spring but approx. 3 weeks ago some of the leaves started turning brown, now all are curled up and brown.
they didn't turn yellow or black, just a uniform brown.
rainfall is normal here, not overly hot and i see no damage to tree or insect... tree has been very slow growing and is 6 inches or less at trunk.
not sure what to do?

Answered

Perry County Missouri about 2 years ago