Pigeon seems to have abandoned their nest

For the last 10 days, there has been a pigeon nesting and incubating two eggs right next to my back door. We’ve taken precautions to be extra quiet so as not to frighten the birds and have been fortunate to watch mum and dad swap places continuously over these 10 days. It’s been absolutely lovely and I feel so privileged to have it only 4ft from my kitchen door! 
we become like human parents, watching over this little family! It may sound silly but we’ve become really invested in watching this amazing thing develop…..

sadly, for reason we are unaware of, both mum and dad seem to have not been near the nest since the early hours of this morning. 
the two eggs are still in the nest, but I’m getting very worried. I’ve looked literally every 15 minutes all day today.

can I do anything to avoid these eggs getting destroyed? I’ve been in awe of the dedication I’ve seen since I first noticed the nest, I fear something awful must have happened. 
so so worried Worried