I found several dead drones on the ground outside my hive. In addition there were white grubs and some underdeveloped drones scattered on the ground as well. I saw workers bringing the Bród from the hive and dropping them on the ground. The attached pictures are representative.
Looks like chalk brood to me. Most common reason is chilled brood - opening the hive when the weather is cold/rainy/windy, or a damp/leaky/shaded hive. Second most common reason is a “typhoid Mary” queen bee, spreading the infection around the hive.You are the only one to have the information from your own hive to decide which. 
Typhoid Mary” Queen bee? That’s a new one for me and I can’t find it in any of my bee books.
That looks like the bees could be cleaning up SHB damage to me. Beetles find drone comb the easiest to lay eggs into. A strong colony can overwhelm a small outbreak & clean it up before it gets out of control.
Brick, can you post a close-up photo of those white grubs?