Nesting Pigeon - Part 1/2

I came back home from my vacation, opening the window and hearing a flap of wings, I caught a glimpse of a pigeon, who got scared, flying away.

On the ledge of the window there was a small nest made of several short twigs; and inside of it two small yellowish eggs.

I moved the nest a little to the side, being careful not to hurt the eggs. I decided to put a camera next to it and document; to see what happens, hoping the pigeon will get back and take care of her eggs, and hoping I could maybe eventually after several days - catch the eggs hatching on video.
She did came back.

But on the morning of the 4th day - something happened. Something that put an unexpected end to my little "urban nature documentary"...

This is part 1 of 2.