Elm trees are susceptible to several pests and diseases, plus can be stressed by urban/suburban growing conditions, so it's hard to make a diagnosis from the description alone. Given the age of the trees, we recommend you work with a certified arborist to assess the condition of the trees in person. Before hiring, you can ask about their experience diagnosing Elms in particular, since some arborists have better diagnostic experience or more extensive training than others. Arborists cannot cure or treat every condition, but they can help to narrow-down a diagnosis, collect samples for testing (if needed), and look for sources of tree stress that might be compounding the problem or making the trees vulnerable to attack.

Miri