Unknown Species, Any help ID’ing Appreciated

While out for birding along the Matchedash Wetland Trail in Matchedash Bay, Ontario (Nearby Coldwater, Ontario) this morning I accidentally flushed a mature bird off of a nest that was located in a derelict Milk truck from the 60’s or 70’s (If my guess is right) unfortunately I was unable to get a clear look at the matter individual before it flew off out of a broken window. I
I took a quick cell phone pic of the nest to see if there was any eggs or young in it; The photo revealed 2 Eggs and 2 Hatchlings.
My research so far has turned up the possibility that the egg on the left is that of a Black-Capped Chickadee, But I am unsure. (My knowledge on nesting/identifying eggs is weak).
I am also unsure about the egg on the right, and the hatchlings.
any advice would be greatly appreciated!

Thank you in advance,
Jack