Experts and BHG readers answer.
Chinese Cherry Tree
Without more information it's almost impossible to help here. Your tree could have suffered winter damage, which is most probably the problem. Although, you don't say where you live so I don't know what kind of winter you had. Winter kill often shows up after the plant tries to put out leaves. Or, it could be another environmental problem due to the soil around that particular plant. It's just impossible to know. Flowering cherries are not long-lived trees and if these trees are over 10 years old, it also could be that it died of natural causes."