Most likely the spring freeze I assume you mean "leaf out" not simply bloom. It likely started to come out before the freeze in march and got hit...If you didn't get the freeze others here can help you but I can tell you it is not uncommon it most likely had a disease going for a long time like vercillium but somehow was shocked maybe by the winter and such opportunistic disease took hold and zapped it ...Either way I would trim off all the dead and dieing and any branches that are encircled in black NOW ( DO NOT wait til fall/winter as many will tell you is best time to prune you don't want it to spread), burn or otherwise dispose of this trash and don't leave it laying around,disinfect cutters with alchohol ( I use purel hand sanitizer I keep a pump in my shirt pocket and squirt it on ) between each cut ...as I said it may just be the freeze...but that too has cased oppotunistic diseases on several of my trees ...no need to take chances... David