Chickadee tragedy (?)

I snuck over to peek at the chickadee nest, and, the horror!  The dead tree was snapped off right through the nest!So much for super secure :(  The chickadee’s nest excavations, that made the wall of the tree 3/16” thin on one side, must have weakened the tree too much.  We’ve had some wet and windy days.I studied the scene and found no trace of violent death from the tree snapping or predators later.  Not a feather, nor shells, on the ground. The top of the tree was lying next to the base.One tiny poop and one wet feather in the nest- it seems improbable that she raised her young slyly enough for us not to notice comings and goings and they got out in time, but I can hold out hope.The nest is almost wholly built out of my hair and fibres I recognize from our Icelandic wool blanket and our fleece sheets.  Incredible.  Basically he felted together a little bowl.  I’m glad they benefited from our intrusion here, then.Once I saw him on the ground outside the camper door, gathering a few hairs and a tuft of wool that’d been swept outside.  He was really working at it, trying to tug the little tangle loose from where it was stuck on twigs and dirt.  Each yank and he’d emit a little “eep”.  The hairs were good and stuck and it looked frustrating.  “Eep, eep, eep, EEP!”  Something I wouldn’t even see- a few brown hairs on the ground- and that little bird spied it.By the barn, the robin is very sly while feeding her chicks- HW has often worried that she hasn’t been around, but she clearly has been around, enough to rear up clutch #2 to a full feathered trio.  Clutch #1.  They’ll be out of the nest any day.  I should have taken a picture on the day I discovered the little pink wigglers with bruise blue eye bulges.  There were only two, sharing the nest with the third blue egg,  and I assumed that the remaining egg was a dud.  But no, it must have been the day they were born, and the third had not yet hatched.  They barely fit in the nest now, overflowing it.