Dash somebody’s hopes
Definition 1 of 1
Pro Tip 1/3Emotional Impact
This phrase often carries a strong emotional weight, implying a significant letdown. 
After months of preparation, the competition's cancellation dashed her hopes.
Pro Tip 2/3Unexpected Events
Use when an unforeseen event causes the loss of hope, not just general failure. 
The discovery of an error in the application dashed his hopes of getting the scholarship.
Pro Tip 3/3Specific Hopes
Best used when someone's hopes are focused on a specific outcome or opportunity. 
She was the favorite to win, but an injury dashed her hopes of a gold medal.