Some  crabapple trees have not blossomed yet.  I would be patient.  If you see buds you are most likely going to see blossoms soon.  

Another possibility is that it was damaged by frost and that would mean you won’t see any flowering this year just green leaves.  The drought has caused many trees to underperform so be sure to water trees during drought. These particular crabapple trees are generally drought tolerant and overwatering can cause disease.

Finally in the most extreme cases, there is healthy new growth in spring which suddenly shrivels and dies. The tree has enough stored carbohydrates in the wood to get the buds growing in the spring. But the underlying vascular tissue that conducts water has died or been significantly injured. When the first warmish days arrive, and water is needed, the buds wilt and die due to a lack of water from the root system.

So patience and careful observation are needed at this point.  

Thank you for the response.  We are not waiting on flowers on tree we are waiting on leaves.