I'm thinking of a predator came, ate the egg, the shell later was cleand up by the robin.

That's what I was truly afraid of. So sad. The tree is in such a supposedly "safe" place. I do believe they have begun nesting in another tree nearby, but I'm not going to look so as not to draw attention from crows, etc. I know I can't move the nest that was attacked. It' now abandoned, and I know they won't return, nor will another robin use it. It's there, in the middle of a weeping apple-blossom tree with leaf coverage draping it, a beautiful empty nest. Thing is, the day before I thought about putting a squirrel baffle around the tree, just in case. My neighbor has a feeder waaaay out back, and it draws tons of blackbirds and I did see a squirrel in her backyard. But the tree the robins nested in was so close to our house, actually touching our window, and anything coming near was freaked by my highly-trained German Shepherd Dog, (especially cats) except for the robins. I know there are laws about removing empty nests. Will they ever return and possibly rebuild on top of it? Or does it stay there....a reminder of what could have been. Wish I'd taken pix, but I didn't want to disturb them. Should have added the baffle. I know nature takes its course, but there are small, non-intrusive things we can do. Missing the sweet sounds of the male!

Ciaron,
You did the best you could,...like staying away and not pay any attention.
I remember a couple of years back here, it turned out worse, we were also watching from the inside of the house, a robin nest with babies, high up on a Colorado spruce tree. One day, junior saw from he's bedroom window crows cleaning out the nest.

This happens allot, one thing you can, console yourself by seeing it this way,...it's still early in the season and birds have another chance or two starting over.
I also think, birds have a better understanding in this matter then we do.

Sure it hurts, we like to grow shrubs & trees, helping them out to find a suitable place raising a family and then all get's destroyed,... feeling like that we've failed.

Even with the metal flashing's it might not have helped, squirrels can jump far from the roof etc.

I'm about 99% sure that the old nest never get's used anymore.
Sometimes they rebuild but they prefer new.

Now,... I have a idea for the old one,
get some chocolate shiny Easter eggs and put in, just to see, who is next to clean it out. I can just see that in a couple of day's they would be gone, and to capture the culprit, have some motion cameras I could set up...if the nest is not too high.
I'm sensing already who it will be,...Magpies!

Hopefully better luck next time,.. happy birding!

Thanks so much for your response. To my surprise, the robins have taken up even closer to our house! Directly on our front porch and under cover, we've had two artificial ficus trees tightly stacked together in the corner. I was stunned when I opened the front door to get a package, and a female robin flew out from the ficus! Then later, I saw the bright male through the window. There is a nest, and the female is in it. My German Shepherd Dog has taken to lying in front of the door and seems to almost be "protecting" the robins in a way. He began barking a lot earlier this morning, and I saw some of the woodchips a bit messed on the front walk. This was in daylight. I thought a package had been delivered, but nothing there. My dog scared something off...I've never seen a cat nearby. If I open my door, the faux ficus trees are almost inside of our house! I'm not using the front door now and will enter and exit through the garage. I was wondering if I place some of my dog's fur around some shrubbery if that will deter squirrels, etc......my dog used to go after them when we lived on the Great Lakes (just moved in October)....he's not a fan of anything (short of the robins) coming to our front door "uninvited." So now....if something tries to attack the nest....it's literally at my front door. I still don't know if that will protect them, but they are really wedged in the corner in the fake ficus trees branches, and the trees would not be able to support a cat (I'm concerned about them supporting the new nest). My dog is at the door as I type. Very interesting. Hoping for the best....will allow them their privacy while my German Shepherd Dog looks through the big bow window and barks at whatever was out there. He does scent work, and is also our security dog....maybe with his help, the robins will make it this time.

I had Robins nest right outside my kitchen sink window last year. A couple years before that Chipping Sparrows nested in this shrub. I don't really like the shrub, because it tries to swallow the house, but the birds seem to like to nest there so I just prune the heck out of and leave it there.

It was great to watch the Robins as they progressed. The total nestlings went from around 4 to only 2 by the time they were ready to fledge. I don't know what happened to the others, but perhaps they were weaker. One morning I looked out and they were gone - and it appeared that something had "pulled" on the nest because it was tipping a bit. I think they fledged during the night, perhaps because a predator approached, but they were ready.

I dunno if anybody's going to nest in this bush this year.

I *thought* it was the robins nesting on the front porch in the artificial ficus trees, because I'd seen a male robin fly away from it. But....I have now seen it is a female cardinal! She's very protected, but I haven't seen the male coming to feed her. Am a bit concerned about that, but I'm not watching all day long, and I have heard cardinal calls here and there. The window washers freaked her out earlier, but she is back and I'm about to block off my front porch so people won't frighten her. Just a bit concerned when her eggs hatch....I don't want to draw predators with bird seed, and my neighbor's feeder way out in back attracts a lot of birds, so the male cardinal might be bringing the seeds/berries/insects to the female at some point, but I have only seen a male cardinal out back of the house. I am amazed at the nest work...how it is so oblivious and you can only know the female is there by seeing her beak (if you know where to look). Okay, so can I be sure the male is feeding her? I don't want to draw any attention to the nest.

Great news but I wouldn't' know.. we don't have Cardinals up here.

Good luck!