The last few days my bees were active and flying when it got warm enough, now there are about 2 pounds of dead bees on the ground and on the bottom board making entry and exit impossible to the bees.
I cleaned out what I could, there's no smell they have plenty of stores, what could be the reason? They died in a matter of a day or so.

I opened the hive and there are about a 1/3 of the bees left and I don't know if the queen is alive. I also have a nuc thats doin just fine. Any help would be appreciated. Thanks